Nope, Sylar's watch is round, Peter's is square. Plus it doesn't have the secondary numbers or the date facility that Sylar's has. And Peter usually wears those turn-up kind of jackets/coats anyway.

This, however, doesn't make me rule out that Peter could be putting himself in place of Sylar. When he dreamed about flying and Nathan, he still wore his own clothes - the ones he wore on the day. But he wasn't the one flying (until the last minute) it was Nathan. So we'll see ;)