Back when the news hit about Rockstar hiring people for PC ports of their latest console titles and perhaps the highest quality experience on the PC, it was very well discussed but with time nothing hasn't yet officially got confirmed except for the fact Dan Houser saying a PC version of V is “under consideration”.
Now, may be Rockstar is busy with some console title (RDR most likely) to release for PC (likely on new Engine). Once they are completed, Rockstar may start working on PC
and next-gen releasesfor GTA 5.
Just a wild speculation since for some reason they are not saying a single damn word about PC plus releasing SA on mobile clearly gives a little evidence that they are indeed working on Ports of popular titles to PC/Tablets/Mobile.
If it turns out to be true then we have a very long wait ... long enough to be precise.
SA Mobile is being developed by War Drum, the only way it potentially affects GTAVPC's development is them using Rockstar internal QA teams.
The news about Rockstar hiring PC developers was regarding Rockstar Leeds, the studio that ported L.A. Noire to PC. It's likely they are the ones also porting GTAV. The last release by Leeds was the iFruit apps for mobile phones and was likely a small team within Leeds as opposed to a whole studio effort.
Redemption has been mentioned a few times, it's simply not coming. The version of the RAGE SDK it was built on had no support for PC and would be expensive to go back and port it when newer version of RAGE do have PC support. GTAV on the other hand was built on the same newer RAGE SDK as Max Payne 3 was (as noted by Rockstar is a few different interviews) and it obviously does have PC support.
And yes, Rockstar is working on GTAV for PC. I can't believe there are still people disputing this.