Aww. That's too bad. But, on the other hand, I can see why. I used to love this show, but after a few seasons, it got a little old. Luckily, Mike has a lot of irons in the fire and he certainly won't be hurting for work.
They should / can make a few new specials every year. ABC canceled Extreme Makeover: Home Edition and they have brought it back for the holidays season.
It was about time the show ended, I think. At first it was a fun program, but after a while it seemed like they were scraping the bottom of the barrel (no pun intended) to find dirty jobs for him to do.
The series had a long, healthy, successful run, but I think its cancelation was long overdue. They must've run out of original, interesting ideas quite some time ago.