Well here's the links to the latest patches... We haven't gotten one in a while, but most people seem to think that THQ's holding this one up.
To auto-update use GPGNet, but that takes forever because GPGNet patches itself too.
Ima assume you have the retail games (3189 and 3596) The version number is in one of the corners of the main menu.
SupCom patch
FA patch
You want them because they remove the DRM and fix the balancing (mostly).
The expansion pack is supposedly canned, but Supreme Commander 2 is being published by Square Enix, so I expect something good.