Oh, I'm sure the _Doctor_ isn't interested in a mate, he's still carrying that absurd torch for Rose. Him not wanting a girlfriend was also the problem with Martha - he knew she wanted him, but didn't reciprocate, just led him on for his own ego, and that plot was a pile of crap. So I'm _really_ hoping they're not making Donna love the Doctor, but I'm fairly sure they're not going to make the Doctor love her no matter what.