Cant imagine why it wouldnt be. Crusie control circuits are actually simpler on manuals than automatics since the cruise doesnt have to worry about the slippage from the convertor on a stick.
Both my cars have cruise - the 'Bird is a 6-speed, and the 65 Mustang is a 5-speed. Cruise is and always has been available on both manual and automatic.
I just wish more people would use their cruise. Most of the time you get behind a car on a 2-lane road, their speed is constantly going up and down. That wstes gas, too. Economy is probably one reason cruise is standard on the new Mustang. Good for them.
I can't stand that. Especially when you go to pass then and they speed up so you can't pass them w/out speeding. I actually use cruise quite often to keep me from going too fast. I have a feeling I'll be doing more of the same once my 05 GT gets broken in.