An update to Team Fortress 2 has been released. The update will be applied automatically when you restart Team Fortress 2. The major changes include: Added 64-bit support for Windows/Linux client and server Should include performance improvements for most users Bugs can be reported here: Fixed an exploit related to uploading invalid custom decals that would crash other clients
Portal and Portal 2 are still 32 bit. Newer mods based on Strata are 64 bit.