WZ recently reported on Jeff Hardy's TNA contract situation, which you can read at this link.
In an update to this developing story, Prowrestling.net has confirmed that Jeff Hardy's contract expires in February of 2013. When his contract expires, his first choice would be to re-sign with TNA. If his offers are met, you could imagine he would return to the company. He has been vocal on how pleased he has been there, and he likes the lighter work schedule.
Although WWE is not out of the question, it looks like they would have to offer Jeff a considerable amount of money more than TNA.