Have a look at the .com site and look over the technical pages. Off the top of my head the only three changes I can think of are the timing chain tensioner, a .4:1 increase in compression ratio from 11.8 to 12.2:1, and the 22mm offset clamps.
Most who have either switched to the 22's on their 09, or who have ridden the 10's say the handling is better with the 22's. The 09's came with 19mm offset clamps, which offer more trail and therefore in theory would make the bike more stable. Also, the 19's put less weight on the front, all things being equal.
The 22's offer less trail, and put a little more weight on the front, again, all things being equal. Therefore, the 22's should provide quicker turning, and also be less stable, but should have a bit more feed back through the bars.
I don't know if they valving stacks have been changed or if the spring rates have been changed. If you are over 165-170 pounds you need to spring the bike for your weight. Also, IHMO, if you are riding relatively faster terrain, and are a good rider you will need to see out the services of a good suspension tuner and have the suspension set up for you, the difference is night and day. Please see my ride reports DaleEO's 09 570 for a description of my set up and the observed handling improvements. I will tell you that after seeing my suspension guy, my 570 is the most stable bike I have ever ridden, and it will still go where ever you look.
The only bike to have major suspension differences in the 2010 line up is the FX. It has the 14mm closed cartridge forks like the KTM XC line, and also has the complimentary set up on the shock as well.
