it's true, open up \StarCraft II Beta\Mods\Liberty.SC2Mod\Base.SC2Data and see for yourself!!!
it seems blizzard likes the custom AI enough to save us all the trouble of downloading it!
really?
No it doesn't, you don't have to replace the AI every single time you download a patch, and most, if not all the launchers replace that file every time you play a game using them.
oh, that would explain it. i didn't think the launcher replaced the original file.