He had Diverticulitis which is a pretty big deal and he is not only a recovering alcoholic, but has also survived two bouts of cancer (or was it one bout and one scare... either way). So for a guy in his mid-50's, that's alot of health shit, and it's got to take it's toll and make for a longer recovery time.
I imagine Troy is spot on.
Obviously Van Halen have made a rod for their own back with all the shit over the years, so now if Eddie's health takes a turn for the worse or Wolfie has exams to finish and a chance to tour with his friends, the forums light up with rumours of Dave and Eddie hating each other... But i think it seems fairly obvious that it was going to take some time to get over that before they can tour again.
Niv