I'm not saying that you're saying that I said that Nightstalkers is wrong, but...
And now a serious look at the card:
If you can tutor every turn for enchantments that act like silver bullets (planar void, righteous cause, decree of silence, solitary confinement) and win conditions (form of the dragon, mobilization) that is very good indeed and
can win you the game. In Kamigawa block, your could tutor for a Honden each turn.
The interesting part is the horrible drawback. Can it be circumvented? Cards like Aether Vial and cycling triggers still work. And there is rumored to be a cycle of creatures in Saviors that you can discard for an effect (no card drawing). It's called channel according to mtg salvation.
See here...
Makes it more interesting doesn't it?
Whoa, how nasty would an Astral Slide deck be with this?! You can tutor for Astral Slide and Lightning Rift and still cycle all your cards away.
Damn!