Tor 0.2.6.3-alpha is the third (and hopefully final) alpha release in the 0.2.6.x series.
There's a new Tor 0.2.4.15-rc out and all of the packages have been updated.
There is a new alpha-release of Tor Browser, based on tor 0.2.4.12-alpha. Alpha versions of Vidalia Bundles and Expert bundles are also updated.
We have some test Tor Browser Bundles available for testing! They contain Firefox 17.0.2esr which we're planning to switch to in February.
The alpha Tor Browser Bundles have all been updated to the latest Tor 0.2.3.20-rc release candidate as well as being updated with some bugfixes.