I've sucessfully flash the google talk with video to the original stock rom.
manually go to the link below, as i'm not allowed to post any link yet
and look below the universal packages for gingerbread, below 20110828, there is a google talk with video / voice chat, flash it by using CWM
when I first install this app by CWM, the google talk just force close when i start it, after that i uninstall the original google talk by using Link2SD, and flash it the file ablove again, and it become all right.
from the post it said, due to this version of google talk is not stable, that's why they don't include in the official update, my experience from it is ok, just some time it force close when you video call some one, but it's not often, so i think is ok to me.