I have a U2412M and no backlight bleed. I also have an older U2211HM that does have some flashlighting in one corner.
Some people complain about "IPS glow" from the anti-glare coating the Dell panels have, but unless you're particularly sensitive to this you probably won't notice it.
As for ghosting or motion blur, I've never noticed it even slightly, but I don't play FPS games.
You have to remember that the trade off is that you get much nicer contrast ratios and colour from an IPS monitor. TN panels will seem washed out and drab after you get used to IPS.
As
aaksheytalwar suggested, you could also get a decent 23" 1080p IPS (for around $200) if you don't wanna shell out for the 24" 16:10 aspect ratio.
The Blackwidow is definitely a better choice than the Lycosa. At least it has mechanical switches, even if it is gaudy. If you're a serious gamer, you might want to consider a tenkeyless like the CM QuickFire series. Better build quality than a Razer and better ergonomics.