Each class will have about 12 talents.
Each talent will have a max of 20 points.
You will get a talent point every time you level which means a total of 98 talent points.
The talents will generally be designed to be maxed out since most will unlock a special bonus at 20 points.
Talent trees can be mixed and matched if desired.
Only one point is required to move up a skill tree.
This means you can max 4 skills, if desired, and then you have 18 points to spend on whatever you want.
Talent trees will have 3 distinct "branches" or "builds".
For instance a warrior has a stalwart tree, a berserker tree, and a gladiator tree. Note that none of these details are final. Values shown are maxed at 20 points:

Stalwart:
Kick - +60% interrupt chance, +40% damage @20 double hits
Pummel - +40% of shield armor as damage bonus @20 slows target for 5 seconds
Bulwark - Reduce cooldown by 1 minute @20 counter-attacks all physical attacks
Shockwave - 40% of shield armor as damage bonus @20: double hits

Berserker:
Slam - Loses stun but 60% damage bonus, @20 hits 3 targets
Hemorrhage - 40% damage bonus @20 hits 3 targets
Frenzied Rampage - Duration increased 10 seconds @20 Triggers rampage automatically when you use subjugate
Absorb Spell - Loses health absorb but converts to a reflect AE on all targets

Gladiator:
Avenging Strike - 20% damage bonus
Enrage - Triggers amplify damage upon use @20 triggers a 3-second frenzy
Triage - Reduce cooldown by 60 seconds @20 increases fury also
Decisive Blow - 80% damage bonus @20 hitting 100 fury activates decisive blow

Looks pretty awesome, any idea on a percentage of completion?

Warrior's using shields, eh?

As of right now? About 0.005% complete.