Of course such a huge title will be released on best platform - PC. I see it also released for next gen consoles.
The only reason why they are releasing every title couple of months after consoles is to of course -- make money. Another thing that's up my mind is that we all know they had to cut some features due to hardware limitations of consoles, we will probably enjoy better version of it on PCs and experience the full joy of the game; drive physics and loads of features. For those thinking it will not be release on PC platform, my question is why shouldn't they? They would lose a lot of profit and a lot of fans. This might end up as most selling franchise, good old Los Santos. GTA:SA is still very popular judging from multiplayer mods MTA and SAMP.
Altho if they don't touch the vehicle physics I'll be very disappointed, seeing how it is now on consoles, just crappy. GTAIV had the best and I enjoyed driving those cars.
tl;dr
GTAV IS COMING ON PC!