Don't count on a next-gen version though, to transfer the world of V into next-gen will take a lot more than 6 months (that's if they are planning on doing so)
The "next-gen" consoles are basically locked down mid range PC's with a "custom" OS. Both Sony and Microsoft are using x86 CPU's and an AMD GPU. So with this in mind it would not take them long to port the PC version to the Xbone or PS4. In fact the architect of the PS4, a Mark Cerny is on record as saying :-
Anecdotally for the indie titles I’ve been hearing 4 weeks to bring a game from PC to the PS4, which is quite fast. For some of the AAA titles I’ve been hearing 2 months, which is also quite fast, and that has really helped us in creating that strong launch line-up.
This is one of the main reasons why it is likely there will be a "next-gen" version because it would be incredibly easy for Rockstar to port the PC version to the "next-gen" consoles.