I presume any plans are far from set in stone (even though a few massing models/CGI images are doing the rounds, certainly if, as suggested, some are being to used as bait for future players).
Be nice to think 'they' (ADUG, MCC, NEM) put out a worldwide design competition (as they occasionally do in the city proper).
I had a quick look at various schemes planned for Abu Dhabi (amongst other places in the world) and the work of Zaha Hadid would be very welcomed my me :)
Incidentally, Zaha Hadid did some work for the Manchester International Festival last year (the acoustically engineered concert hall).
Point being, City really shouldn't worry about reaching the hazy heights of a 100,000 seater stadium to turn heads around the world...conversely a 60,000 stadium designed by an 'unadventurous' firm of architects (and there's plenty doing their uninspiring work back in town) won't do any grand plans much justice. I won't name names, but a recent flurry of 'super stadiums' planned for the uk are essentially modern sheds attached to a monstrous 'Betterbuy'.