Google's ambitious newspaper scanning project promises to dramatically increase the amount of primary source material online. Very exciting news, but at this point in the project, you have to get pretty specific if you want to see examples of the scanning they've done.
Google's announcement suggested two sample searches for the Google News Archive that would return results from their scanning project: Nixon space shuttle and Titanic located. These searches produce result sets with articles from the scanning project near the top of the list, intermingled with articles from other sources. Queries that produce similar results are hard to come by (quick -- someone prove me wrong!).
Searching directly within the titles Google has stated it is scanning produces a healthy group of examples: try the Quebec Chronicle-Telegraph, the St. Petersburg Times, and the Pittsburgh Post-Gazette. Likewise, a site search of "http://news.google.com/newspapers" seems to bring up everything that has been scanned thus far.
As a side note, if your hopes for LSTA-sponsored newspaper scanning were dashed (yet again) this year, check out Google's News Archive Partner Program. There has to be a role for Wisconsin libraries here, don't you think?