If you've hung around ENWorld or the WotC forums during 2006 and the early part of 2007, the power of players over DMs in 3e has been a consistent forum topic, because in the previous edition the power of players has increased along with the more consistent and encompassing rules.
Concurrent with it has been the difficulty of DMing higher level encounters, giving rise to DMs often giving their players more jobs to do in helping him keep track of all the statuses, hit point damage, etc. on the monsters. Habits can be hard to break.

I know for myself, I let the players help me keep track of spell durations, hit point damage accumulations, etc. on the monsters by slipping scrap paper chits under the monster minis, because this helps us both when more than five or six monsters are on the table.