Aye, but you're an eternal optimist Ash!
Defensively I actually think is where he's improved the most. He's always been exceptional positionally in defense, breaking up play and making interceptions. But that came at the expense of closing down and making tackles I thought, he would remain disciplined and not get 'stuck in' etc. Alot of fans crticised this as being lightweight, which was a fair accusation to throw at Carrick and when you consider that many fans would compare him to Keane, unfavouravly, this stand-off approach to defending wasn't attractive. It annoyed me at times to be honest, it seemed like he lacked the determination or mentality to win the ball and given his quiet nature a lot of people took this as being weak etc. This seasons been completely different, granted his passing has improved but it's his attitude change which has impressed me most, he's made the most tackles per games than any other player bar Rafael, and predictably has the highest interceptions per game.
Whether his closing down is a result of tactical instruction or a new attitude by Carrick I'm not sure, but he's putting himself about far more frequently and winning the ball all over the pitch. In addition this hasnt come at the expense of positional indiscipline and so he's consequently still shielding the defence and making interceptions. So I agree there was great defensive work done before, but there has been some clear improvements.
Then of course theres the passing improvements, which havent been consistent in my view. He'll play a much more expansive game one week and then revert in other games, or not do it to the same extent. I'd be happy for his pass completion rate to drop into the 80%'s if he maintained his more direct passing at times, because he has the ability to pull in off.
He's probably player of the year so far, him or Evans for me who I thinks been remarkable this season given the defensive injuries.