Let's see what my Android devices say:
HTC Wildfire S: Used it for over a year, no problems, still used as backup phone; got an update just a few days ago
HTC Desire S: currently in use, update a few weeks ago, ICS update planned for later this month
Archos 70IT: Used it for over a year, got about a dozen updates, including an update to Android 2.3, would still be working if I hadn't dropped it on concrete
Archos 80 Gen9: Bought it about 7 months ago, still working fine, got several updates, including ICS early this year
So all of my Android devices get updates (not always in a timely fashion, I grant you that), and last for more than 6 months. I'm to blame for the only one that isn't working anymore (and actually, it's working fine, except for the screen).