Well, Eldar no longer have the 'Seer Council', and the common use of 3 Wraithlords is no longer common.
Mech Eldar is the new power build for Eldar, even with Serpents no longer to allow for quick assaults. I've modified my list below so that it becomes harder than it really is, but should give you a pretty good idea of what a Mech Eldar army can do.
Farseer w/ Jetbike, goodies
3 Vypers w/ SC/SL
*** 21 rerollable Str6 shots (I average about 18 hits and 16 wounds) If kept out of sight of most of the enemy army, this unit can own half the board.
Autarch w/ Jetbike, goodies
5 Shining Spears w/ Exarch, goodies
*** 3++ save when moving fast, the ability to hit&run, and 17 Str6 Powerweapon attacks on the charge at high initiative and WS.
6 Fire Dragons (no exarch needed)
Falcon
*** Typical anti-tank unit of death
Dire Avengers w/ Exarch (Twin Direpult, Bladestorm)
Serpent
*** Take two of these units and unleash 32 Str4 AP5 shots each in one turn. I usually hit with 24 or so shots each, so you're looking at a lot of dead gaunts, guardsmen, whatever. Consider this the Eldar equivalent of the Tau Fish of Fury, someone dubbed this 'Snakes on a Plane'.
3 Eldar Jetbikes w/ SC. No other upgrades
*** Take two units of these. They are very cheap units and are really only useful for scoring objectives and quarters. But, they are very fast, and can help remove that last remnant of an enemy squad.
Prism
*** Take two and see just how fast your enemy starts spreading his troops out. The risk of being on the receiving end of a Str6 AP3 pie plate will send even hardened assault units into cover deep within their deployment zone.
In my experience, the most devastating play has to be Guiding a unit of 20 Guardians w/ Warlock and Platform and Dooming a unit within 12" of them. In my case, that was 44 shots with rerolls to hit and wound. Even with the enemy unit at full strength and in cover, that was just too much.