I think it's pretty clear that Romney is becoming more conservative over the arc of his political career. Is he a movement conservative? No. Does he still need to move right on some issues? Yes, but he seems to be traveling in that direction with decent speed.
Mitt governed more conservatively in MA than he campaigned (which is why his reelection prospects looked so dim). He said the experience made him more conservative. Given the nature of politics, I understand why some would view his transformation with skepticism. But I also think it's perfectly reasonable to consider that his conversion is real and ongoing.
The man clearly has the skills to be a turn around artist extraordinaire. With his apparent ideological transformation he could end up being one heck of a president.