While it's true his first four games (3 as the starter) weren't the best, consider that because of the lockout, he had no training camp to learn a new offense and because he only played with second and third string players during pre-season, no reps with the starters. So those first four games were basically his pre-season, his time to get on the same page as his teammates. He's played very well since.
As for the Thanksgiving day game at Dallas, I think he played as well as possible considering he had Cowboys in his face all day. I really didn't think Miami had a chance to win that game. Dallas has a top 10 offense and defense, not to mention it was on their home field. The bottom line is the Dolphins had the lead with 3 minutes left and the defense failed to hold. Tony Romo was hot. He was completing passes while he was being mauled. It's hard to overcome that.
It's conceivable that the Dolphins could win 4 of their last 5 games. That might put them out of the running for one of the top 4 QB prospects. If that happens, and Matt Moore has played well and been consistent during that stretch, would you be comfortable with him returning as the starter in 2012? Sometimes quarterbacks take 3, 4, 5 years to blossom. Drew Brees didn't blossom until his 4th year. Kurt Warner was in the Arena Football League and NFL Europe for 4 years before he blossomed into an elite QB. I am in no way, shape or form saying Moore IS going to turn out like Warner or Brees. He could just be a good back up. But just like Warner and Brees, you never know.
And in case you are wondering, YES, if the Dolphins have a chance at one of the young QB's in the draft, take him no matter how well Moore plays in the final 5 games.