Not really but people are saying It could be back to San Andreas. Personally I'd love Vice City. GTAIV is a great game but I'm still praying that Mircosoft's money held back additional features. The endless list of features such as: Turf Wars (not crappy online version), pimping cars, investing, more weapons , planes, skydiving, stealth missions, etc etc
Fingers crossed but I have a feeling I'll be slighty disappointed when Its released.