While the PC version has not yet been released, we’re pretty sure it is going to happen. Anything else would be stupid of Rockstar. The reason why the console version was released first, is that Microsoft and Sony paid a huge amount of money for it to be console only to begin with (this way people had to but the console version first).
Anyway, as soon as the PC version is released, mods will come to. We will of course feature the best GTA 5 mods here on this site, so stay tuned for more info.