Yeah, lots of people are using OAuth. Its evolution from WRAP->OAuth 1.0 has in my opinion been mostly good. However, there are always the details of how something is built that makes you realize, not everything is what it seems to be:
http://hueniverse.com/2012/07/oauth-2-0-and-the-road-to-hell/
After reading the article…go to the last part…I tweeted that all not too long ago. I did the same for REST in SharePoint 2010.
You have to wonder. Who is the "Enterprise" in this case? Hint…My guess is the name starts with an "M" and ends in "T"
Chris