Remember the snafu last month where T-Mobile was shipping out warranty-replacement G2s running Gingerbread? Well, some crafty tinkerers have extracted the build and made it available for all to download. This 2.3 update is the same exact version as the one T-Mobile mistakenly shipped out, so though it isn't "official," rest assured that it is the build that big T is working with. No, you don't need root, but yes, there are some bugs that still need squashing, so as always, download at your own risk. Hit the source link to grab the update from T-Mobile's support community.
Source: T-Mobile Support Community