I'll give you a few right off the bad, since we have been going every year for a while - once a year gives long enough between trips to notice the changes so hopefully I can fill in some of the blanks and soon others will be along to add to it
The new Fantasyland! With the ages of your children I think it's a must do
Some no more Ariel's Grotto or Toontown as you will know, no doubt (not sure how early in 2010) you were there.
FP's must be used within the return window, although there is a non obligatory 15 minute grace period (unofficial however)
EMH at night have been cut from 3 hours to 2 hours
AK no longer does evening EMH but does morning ones twice a week
CRT does character breakfasts, lunches and dinners (so its easier for you to get a reservation than it was a few years ago)
Probably the biggest change is the current roll out of the RFID and
MDE system. There are a lot of threads on the topic on the main Theme Parks board.