So, Google didn't announce a GooPhone today, but they announced that they're part of a partnership to create an open source platform for phones which is pretty much what everyone has been saying for quite a while. OK. Great.
T-Mobile and Sprint are definitely in and part of the "Open Handset Alliance" (which is probably why Sprint recently announced they'd be unlocking their phones). The platform will be called Android and the first handsets will be available sometime next year.
Details are a bit scarce, but you can check out the Official Google Blog and Engadget's liveblog of the announcement for more info.
Money quote from Eric Schmidt, Google CEO:
"Google announces products when they're ready..."
Is that why Gmail, Google Docs and Google Calendar are all still in beta?