Actually I think his jutsus and powers would be pretty much the same except he wouldn't be having any snake jutsus or the V2 curse mark thing. Kakashi is a pretty good trainer and i'm sure he could have helped Sasuke get atleast as good with Raiton as he is now, maybe even better since Kakashi is a Raiton user.
I'm pretty damn sure he still wouldn't get MS until he took down Itachi though.
Acutally the main difference would probably be for Naruto who wouldn't have to go searching for Sasuke all the time
exactly what i was thinking.
edit:
If Naruto defeated Sasuke in the Valley of the End, he would still have access to the Version 2 Curse Mark since his seal Kakashi gave him is based on willpower. He wouldn't have mastered without Orochimaru but he would still have it.
However, he wouldn't have snake summons or his immunity to many poisons.
He probably would have asked to go on a mission to kill Itachi. He still would have seen him die and, thus, unlock the MS.
Yes, he would still have lightning mastery due to Kakashi's tutelage. It might even be greater since Orochimaru doesn't have lightning but Kakashi has it as his natural affinity.
However, with Sasuke still present, Naruto would not have gone to train with Jirayia making him weaker than he would be.
I also see no reason why Sasuke wouldn't master swordsmanship if he stayed in the leaf.
Sasuke would still have his hatred for his brother to fuel him. He would probably hate/envy Naruto, though that would fuel him to get stronger. He'd probably come to see Naruto as a friend/rival again.