This was originally intended as an answer to the practical question of how current use of a term could best be gauged. As such, the answer lists common resources available for that purpose. Google Ngrams/Google Books do not satisfy the demand: being raw statistical data (the n-grams from the Google Books corpus) based on raw textual data (Google Books), inferences drawn from the mess are prima facie invalid and, if sound, only sound as a result of aleatoric serendipity; outside of tightly controlled experimental environments, the textual data as presented via the Ngrams interface is only useful as a biased and poorly focused selection of instances of term use during the stipulated time period.
Other than the painstaking, longwinded traditional lexicographical techniques of gathering and comparing dated uses of terms in context and over time, no technique or set of techniques (that I know of) suffices to address the desired distillation of 'contemporary use' into 'contemporary senses'.
I should stress that 'contemporary use', that is, what you call "current use", although I'm understanding it in the spirit you seem to intend (which is notably parochial), includes all historical use. That is to say, for example, that to the extent that Shakespeare is still read and discussed, Shakespearean usage remains contemporary to that limited extent, however rarely a Shakespearean sense of a still-common term may occur in popular contemporary use.
- In view of the fact that it is a fossil record, should we rely on Google Ngram Viewer as an authority for current usage?
- If Google Ngram Viewer is found to be wanting, what do we use instead?
No (to question 1). Any "fossil record" should inform and condition conclusions regarding "current usage", but the notion that a fossil record is all that is presented when the beast (the literature) still walks the earth is just plain wrong. Google Ngram Viewer/Google Books has limited utility as a collection of corroborative evidence of term use to 2008. Current, that is, contemporary use, is best gauged with a wide-ranging combination of resources. For links to some of those resources, see the following.
- Is there an up-to-date currently-maintained corpus based on newspapers and Web sites for English?
Yes, if "up-to-date" and "corpus" are somewhat loosely used. The "corpus" is the sum total of World Wide Web resources available through general and specialized internet search facilities. "Up-to-date" for these resources is not "up-to-the-minute".
Aside from the obvious general internet search of contemporary journals and newspapers using any of a variety of search engines, free searchable newspaper corpora include the compilation from some US, Australian, New Zealand and Singapore newspapers at Elephind, and the more specialized compilation of US papers at Chronicling America. These each have their strengths and weaknesses, in terms of the results interface, etc. Elephind includes Chronicling America results, but the interface is weaker in some important areas (highlighting search terms, or not, being the most prominent area of disparity). Note also that Elephind includes some papers from as early as 1787 and as late as 2015 (the Elephind date range is a moving target because the Veridian enterprise is ongoing), while the Chronicling America collection is limited to papers published between 1836 and 1922.
Other useful sources of newspapers and other works include these:
- The Hathi Trust Digital Library (contains many works also included in Google Books, and sometimes offers alternative routes of text access where access is limited via Google Books);
- The Internet Archive and Open Library ("10,000,000 eBooks and texts");
- Google Books (this is the base collection for Google Ngram Viewer; I find it returns different results than the Viewer, and so usually check both);
- Veridian (many of these are included in Elephind results);
- Newspapers+ Publisher Extra (some time in the past I gave up on the next paywalled source in favor of this one; I believe the problem with the next source was signal-to-noise ratio, but I don't remember, although I assume my reasons were sound);
- Newspaper Archive (this bills itself as the "World's Largest Collection", but you'll have to pay to use it);
- The Internet Library of Early Journals (limited collection of 18th and 19th Century English journals).
The usual specialized online corpora, such as COCA/COHA (Corpus of Contemporary/Historical American English), Micase (Michigan Corpus of Academic Spoken English), Corpus Concordance English, British National Corpus, etc. (see especially the listing shown at english-corpora.org), should be mentioned. Some of these are listed in other questions and answers at the ELU meta site. (See the related questions and answers listed in a sidebar box associated with the linked question on the ELU meta site. The most comprehensive lists seem to be in What good reference works on English are available? on meta and What are your favorite English language tools? on main.)
For your specific question, there doesn't seem to be an organized and comprehensive answer; the questions and answers on ELU and ELU Meta referenced in my preceding paragraph are more general, very roughly organized, and don't include the newspaper or some of the other corpora I mentioned.
Raw Google Books n-gram data and more sophisticated interface
If you have the chops, the raw Google Books n-gram data is available for use. Unless whatever application you devise includes Google Books lookup and link collection facilities, of course, you will find the Google Ngram Viewer more convenient for many uses.
A much more sophisticated interface than the Google Ngram Viewer for the Google Books n-gram data is available via English-corpora.org.
For your question 3, two very useful corpora only recently (May, 2016) made available are the NOW Corpus of contemporary online newspapers and CORE: Corpus of Online Registers of English. For details see their respective sites, but here are brief descriptions from those sites.
The NOW corpus (Newspapers on the Web) contains about three billion words of data from web-based newspapers from 2010 to the present time. More importantly, the corpus grows by about 4 million words of data each day (from about 10,000 new articles), or about 120 million words each month.
With this corpus, you can see what is happening with the language this week — not just 10 or 20 years ago. For example, see the frequency of words since 2010, as well as new words and phrases from the last few years.
This corpus contains more than 50 million words of text from the web. Unlike other corpora from the web, which are just big "blobs" of data, this is the first large web-based corpus that is carefully categorized into many different registers.
... You might pay special attention to the comparisons between registers and the (new) virtual corpora, which allow you to create personalized collections of texts related to a particular area of interest.
In addition to these recently released corpora, one of particular interest for researchers looking for information about contemporary informal usage is the Corpus of American Soap Operas:
The SOAP corpus contains 100 million words of data from 22,000 transcripts from American soap operas from the early 2000s [ed.: 2001-2012], and it serves as a great resource to look at very informal language.