Xeon on 30 June 2016
I would prefer it if they still focused on the single player aspect of it. Obviously, the online component has been extremely successful for them and it's nice to see they have supported it really well. However, I really think the stories they tell through single-player are generally well done.
Edit*
I misread the first part of your post. An MMO mode could be interesting as long as it doesn't hinder the single-player mode. Rockstar have proven they have the chops to make an engaging online experience but and MMO is a different beast.
