Orochimaru saw through Kabuto how messed up his ways were and how he screwed up a kid that would've been decent in his own right but chose to see his master as a god and emulate him. Orochimaru's goals are to learn all the jutsu's and secrets the shinobi world has to offer, he needed bodies in the past because of the jutsu he was using.. he has no need for them now since he has senju DNA (supposedly) and Zetsu at his disposal.
His motives to obtain an Uchiha body was for 1) to gain the sharingan so he could unlock it's secrets/copy jutsu and 2) to get into the shrine.
Well since he has the perfect body(s) now, he won't have to worry about dying unless he is fully sealed... so he has unlimited time to learn jutsu, so 1 is crossed off. Sasuke led him to the shrine and he got in, so 2 is crossed out.
I really don't think he will be a main villain, he hasn't really been since Akatsuki came around and then when Obito/Tobi and Kabuto took the reins. No one in this series has been a true villain other than Hidan(bloodlust), Kakazu(greed), Obito(although recently that's questionable... and has been really since all he wants is peace)... and anyone else I missed. They all turn out to have a revelation of some sort.. which to be honest is the whole point since Naruto is supposed to change the shinobi world one person at a time I guess.