Hot off the press! (is that still an expression given the apparent demise of newspapers?) Mashups: Google’s Adoption Makes oAuth a Must Have for All Apps. This right after MySpace announcing support for OAuth with their Data Availability initiative the day before.
IMHO, this is huge for data portability, in this case, OAuth support for all Google Data APIs, everything from Gmail contacts to Google Calendar to Docs to YouTube. Bottom line, users no longer need to give up their confidential Google accounts username and password to 3rd party services in order for the 3rd party services to access their data on Google services. I suspect that Google is doing this because it helps them become the service provider of choice using an open and standard means of authentication hence channeling even more traffic through Google servers that they can figure out how to monetize later, much like their Friend Connect effort.
This is a major win for OAuth, in fact I would say that OAuth has now become a bigger player than OpenID in the space of data portability technologies. Given the recent history of big players announcing back to back support of similar features, I predict (ok I hope) that Facebook and Microsoft will follow suit.