Reason #1: The new dashboard is three steps backward in aesthetic design.
Reason #2: The default fonts are harder to read than previous versions.
Reason #3: There are too many different fonts.
Reason #4: WP3.2 doesn't handle graphics consistently (some load, some do not, then do, then don't--no rhyme, no reason, no pattern. Limited to smaller files generally--like the WP logo on the log-in page, or dashboard left menu icons).
Reason #5: I do not like having to click twice to log out of Google; I like it even less in WordPress.
Reason #6: The more I use WP3.2 the more I hate the look of the dashboard.
Reason #7: Red is the wrong color for update count noticing. If you didn't notice black, you shouldn't be an administrator.
Reason #8: For those who already selectively updated, the new update process brings little to the table.
Reason #9: The black admin bar was a good option as original issued. Expanding its function(s) seems to be headed toward redundancy.
There maybe more reasons, but this blogging (written off the top of the head) not a research presentation.

Only have 4 sites running WP3.2 (out of approximately 200). In a hoping/holding pattern...

If changes to WP are for security or ease of use, great. Otherwise, there is never an "about time to change the control panel (dashboard)" if the current one is clean, effective, working and pleasing to the eye (WP3.1). Adding an additional dashboard color option other than grey (default) and blue (my fav) would have been well received (light green, for example, to please all the eco-heads).

The Dover list didn't even rise to the level of humor.