Here are the current Protoss units. * got this info from SC2 site*

Builds From: Gateway
Armament: Psionic Blades
Role: Assault Warrior
The basic infantry unit for the Toss

Builds From: Gateway
Armament: Twin Phase Disruptors
Role: Ranged Assault Support
The cool thing about them is they are able to throw up a Energy Shield of some kind, highly affective on Siege Tanks.

New: Stalker
Builds From: Gateway
Armament: Chronal Web
Role: High Mobility Scout / Ambusher
Stalker is a new unit, its mostly a "scout" type of unit. It comes with a very useful skill. It can Blink, teleport good for ambushes/scouting

New:Phase Prism
Builds From: Robotics Facility
Armament: None
Role: Tactical Transport
This unit is able to go into "Phase Mode" Which basically acts like a pylon.
So lets say a group of Marines take out a Pylon and leaves a Gateway unpowered a Phase Prism can come along and go into Phase Mode and power the buildings.

Builds From:StarGate
Armament: Twin Ion Cannons
Role: Air Superiority Fighter
This is basically like the Corsair. This unit only attacks air, it comes with a special power. It is able to unleash a blast to target multiple units but it comes with a price, it leaves the Phoenix crippled and unable to move for a short period of time.

Builds From: Robotics Facility
Armament: Twin Thermal Lances
Role: Heavy Support
Not much to say here, this unit literally moves down infantry like its nothing.
Not so good against heavy units.

New: Warp Ray
Builds From:StarGate
Armament: Prismatic Beam
Role: Long-range Bombardment
A heavy air bomber basically, over a few seconds more beams get aligned and the firepower is increased, it is strong enough to do damage on battlecruisers.

New:Twilight Archon
Builds From: Merging Templar
Armament: Psionic Shockwave
Role: Heavy Assault
A new unit that is created by merging two templar, Has high energy shields and is pretty much untouchable unless your using heavy fire power.
Two Archons can easily take out 12 marines without being harmed.

Dark Archon:
Builds From: Gateway
Armament: Modified Warp Blade
Role: Stealth Infiltrator
Nothing new, invisible unit, good damage, hits ground, slash slash cut cut.

Builds From:StarGate
Armament: Disruptor Pulse
Role: Capital Ship
Okay this is... well by far the most badass unit the protoss has.
You can only have ONE at a time, due to its heavy firepower.
The coolest thing about this is it can open up a "black hole" or warp hole which ever you like to prefer but what it does it literally
SUCKS IN EVERYTHING and destroys it.

Builds From:StarGate
Armament: Interceptors
Role: Capital Ship
Same 'ol Carrier, unleashes its little Interceptors

Builds From: Robotics Facility
Armament: None
Role: Scout
Nothing new here, a small little invisible unit provides vision against other invisible or cloaked units.

So thats about it, I put this together to give you a brief view on the Toss units.