Uh, so the idigitaltimes article's source is this examiner article: 

http://www.examiner.com/article/gta-5-ps4-and-xbox-720-ports-could-be-announced-soon-according-to-report

The Examiner article's source is this gameranx article: 

http://www.gameranx.com/updates/id/14043/article/take-two-conference-call-may-reveal-new-info-on-gta-5-and-xcom/

And this is the content of the gameranx article: 

In addition to their plans with the XCOM series, the publisher may have something to announce about Grand Theft Auto 5. The game is scheduled for a 17 September release on current-gen platforms. Thus far, Rockstar has neither confirmed nor denied whether it will bring the game to platforms outside of the PS3 and Xbox 360. Fans of the series hope that the publisher will announce a decision to bring the game to the PC and to next-gen consoles including the PlayStation 4.

That's...it. "Fans of the series hope". Great. 

Edit:

idigitaltimes also claims an InEntertainment article suggests there will be next gen versions (but they didn't link it..). Found it though: http://www.inentertainment.co.uk/20130419/gta-5-for-next-gen-consoles-details-incoming/ 

Their source is the Examiner article too, lol.

exactly with a game like GTA 5 i imagine it has like over 100 million dollar bugdet with the PS3 and 360 user base i think they will make back the budget and the wii u, PS4, and 720 versions will just be bonus money 

Why is that? 

There is very little bussiness reason behind such a version. We have a console with a low install base and very lagging in sales and momentum. Plus there is pretty much no GTA crowd on Nintendo platforms - no mainline GTA games on home consoles, one spin-off for the DS that outsold the much later PSP port by 300k with a much much higher install base and itself didn't sell gangbusters.

Then there may come developing problems, if this is a last minute decision port with a pretty short development time, we may end up with a sub-par experience performance  and/or graphics wise than that found on PS360 just like on many occasions with launch games, to name Assassins Creed, Darksiders, Batman and Call of Duty. For it to be a worthy game, it would need to be in development for quite some time, with more manpower and budget. 

That all calls for a flop and a waste of money and time.

A next gen port at least has potential, which Wii U version lacks in my opinion and that's why I would be surprised to see one.

EDIT. As I forgot to add. A good reason would be Nintendo moneyhatting the game and covering the port costs, but I cannot see that coming.