Yes you can still browse old newspapers for now but you can't search Google's index. Since Google doesn't announce much about changes I was unaware of this particular change. After some research it looks like this occurred in early December, 2013.
So to sum up you can search for newspapers published after 1970 but can only browse for papers older than that. I would encourage you to read this page from Google Help to see the details on how to search the more recent newspapers if you are interested. The Help page is a bit confusing in my opinion. Furthermore, I have noticed that some pre-1970 newspapers have sneaked in to the results, but they are inconsistent and the numbers of hits are not even close to the number of hits before this change by Google. For example a search that I performed prior to December on one of my ancestor's surnames yielded over 800 results; doing the same search today using the techniques referenced in the Help section yielded only 2. I choose to treat this as an anomaly personally and not something that should be counted upon.
So my friends it appears that the Google Newspaper Archive for historical newspapers is DEAD at least for searching (for now). As I said you can still browse, so all is not lost. And the first comment in this Google Product Forum provides a glimmer of hope.
Yes this has been a wonderful free resource that many of us genealogists have used and thank you Google for that - but this is a bummer.
(Thanks to Missing Merchants from Google+ for raising this issue)