If you want to have an effective
CC Wraithknight you need to do a few things. First off, never take a sun cannon, unless your going shooty. You need a scatter shield of course so take the Ghost Glaive and and
SS. For 10 points you get a 5+
inv and master crafted. Not bad, though the +1 S is useless as your S10 already. Then take a scatter laser if you really feel the need to twin link a single wraith cannon. If you are following the wraithknight with a jetbike farseer, then dont worry about it and use 24" guide to reroll the shots.
If your WK is
CC oriented then keep it cheap, pop transports with the cannons, then assault the embarked units. Most marines cannot wound you. Watch out for hidden power fists and poison weapons etc.. dont charge thunder/hammer termies, shoot them and run away.
Not too fond of spirit/seers in farseer's role. Better off sending him with wraithguard giving them a 2+ armour save or
Ws and I +1. Put them in a Wave Serpent of course, I should even have to say that.
lol 
Serpent shields these days I mean come on... Wraith guard all the way vs wraithblades, depends on your points limit whether you go cannons or flamers, but dont underestimate a large Ap2 blast on those guys so get in cover or bring a farseer for divination forewarning 4+
inv..
However I really dont see the
CC happening as you cant charge out of your transpor,t as it is not an assult vehicle. The Wraithguard are better fire dragons, in both acting as a scoring unit, and an anti-tank. which really
IMO is quite nice.
II would make a wraithguard list like this_
Farseer x 1
Spiritseer x 1
Warlock? x 1-2
Wraithguard x 5
Wave S. - Holo f, Scatter L.
+
Wraithguard x 5
Wave S. - Holo f, Scatter L.
Jetbikes x 6
2 S cannons
+ Warlock - Jetbike/Singing Spear.
or
Dire Avengers x 5-10
Wave S.- holo f, B Lance or Scatter L.
Warp Spiders x 6-8
+
Warp Spiders x 6-8
Wraithknight x 1
GG and
SS
Dark Reapers x 5
Exarch - Night Vison/Fast shot
Vauls Weapon Platform x 3
D-Cannons
Warlock for 2+ cover!
War Walkers x 3
Scatter L. x 6
(sky shield landing pad!!!)
4+
inv.
These are the squads I take and consider to be the most powerful in the eldar army.
Hope this helps a bit. Your list really depends on the models you have or perhaps dont have? not sure. Also on whether its a tournament list or a fluffy/fun list.
Let me know whats going on and ill do my best to help.