I'm not sure about no surprise round, but regardless, if there is a surprise round (and thus flatfootedness), it's a single attack not iterative when coming out of invis. If it's not a surprise round, no flatfootedness, and only one attack with Dex denied.
So just one sneak attack, unless surprise round and initiative is won.
I though all combatants were flat-footed until they act in the round. So if Rogue was standing next to an orc and suprised the orc (lets say the orc thought he was an ally). He would get one attack on the orc during the suprise round. Then if the rogue also beat the orcs initiative roll he could make a full attacks worth of "Sneak Attacks" because the orc would still be flat-footed as it had not acted yet and therefore would still be denied its dexterity bonus.