While I do not think peter can steal Superman's powers, leaveing superman to be far faster and stronger with all his other powers, I do think peter would win the fight. due to freezeing time, now if superman is moving this of course will not work however if superman is isn't superspeeding but standing there waiting for peter, then when peter stops time, superman would be stop, note hiro does this to Daphne in the episode he pretends to killer Ando, and she has no clue if though she can move when time is frozen witch mean superman might be able to as well. Also Peter can enter superman's mind, superman has no powers from an attack like this while telekiness won't work, mind reading and controling will. also all of those vision superman has won't allow him to see something that is invisable and can phase threw objects, has well has him I would guess. Not to mention peter not only dreams about but can paint the future so he would have Kryptonight or teleport superman to where there was lots of the stuff, and would know about red sunlight due to syler's powers of understanding how things work and teleport Superman there, or my personal favorite he could just put Superman in the body of Jimmy Oslon no Real threat now, so I got to go with peter.
also I would love to see a duel between nightcrawler and Hiro with Hiro not freezing time. that would be an awsome fight.