Does concealment allow a rogue to make a sneak attack?

[billd91]

Yes, it does allow you make a ranged attack while hidden, though it doesn't say anything about denying the target Dex to AC.

Being hidden (the target failing his spot roll) makes the attacker, for all intents and purposes, invisible. Attacking while invisible causes the target to lose his Dex bonus to AC. Staying hidden while doing this (and thus keeping the ability to make sneak attacks this way) is extremely difficult, hence the massive penalty on hide checks to remain hidden.