The RAW is that you can Rage and sneak attack. Rage prevents you from doing anything that requires concentration (like spellcasting or maintaining certain bardic music). The obvious area of things disallowed is spellcasting. The ban also extends to any skill or ability that would require a concentration check to avoid getting disrupted.
Note that even if you were to extend the definition to include ANYTHING that can be disrupted by an enemy's attack/AoO, which would actually prohibit you from using Grapple and Sunder (which seems a little extreme to me, but hey, just using as an example) without the Improved feats...sneak attack is still RAW legal. Nowhere in any book is there ever any indication of sneak attack being able to be disrupted. It doesn't matter if you're struck by an AoO in between, it doesn't matter if you're in stormy weather on a boat. You get sneak attack. It requires no real concentration, it's simply limited by the conditions that don't allow for sneak attack -- vitals out of reach, concealment of any kind, immunity to crits -- which is already pretty restrictive.