You get a talent point every other level (10, 12, 14 ect) until level 80, then you get 1 talent point every level til level 85.
Blizzard has cut the fat of the trees (Talents that say give 5% base more damage or something along those lines.) reducing them to 31 point depth.
You cannot put any points into another tree until you have 31 points in one tree. For example, you cannot spec 0/20/21.
The talent tree that you choose to spec 31 points in gives you tree specific bonuses and a signature tree ability. (Ret Pallies gets Divine Storm at level 10, Survival Hunters get Explosive shot, ect.)
---------- Post added 2010-09-07 at 07:13 PM ----------
For more information, go here.
http://www.wow.com/2010/07/14/catacl...nuses-and-mor/ (The link is just a tiny bit dated.)