Thought I'd bump this up as a lot of time has passed.
Qatar qualify automatically as hosts and Iraq, Saudi Arabia, and South Korea are automatic qualifiers as the top three from the 2007 Asian Cup. India qualify automatically as winners of the AFC Challenge Cup in 2008. There is a spot reserved for the 2010 winners of that competition as well, and if India were to win again then the runners-up would take the spot.
From the qualifying groups, Bahrain, Japan, Uzbekistan, UAE, Syria, China and Iran have qualified and I believe there is only one round left with three spots up for grabs. Two of Kuwait (8 points +1 GD), Australia (8 points +1 GB), and Oman (7 points 0 GD) will qualify from Group B - Australia hosts already eliminated Indonesia and Oman hosts Kuwait, both on 3 March. The last spot is in Group E, where Iran have already qualified leaving Thailand (6 points +1 GD), Singapore (6 points -8 GD), and Jordan (5 points -1 GD) to battle it out. Iran hosts Thailand, Jordan hosts Singapore, also on 3 March.
Australia will qualify no doubt, but the rest is a tossup. As a fan of the underdog I would like to see teams like Oman and Jordan qualify, and I think they have a decent shot, so we'll see.