Lol, no it's not at all. Only a homer would say he's a top line center right now. He performed at that level for 40 games, that's it.
Lets just look at stats first (without saying how his 40 points this year has been arguably the quietest 40 i've ever witnessed).
There are 60 top 6 centers in the NHL, give or take. Stepan is currently 33rd in points for NHL centers. Take into account guys below him, not playing with a stud like Nash, not getting the same amount of top line ice time/PP time AND having injuries, as Stepan has played every game.
If you put 7-10 of those centers ahead of him, which i certainly do (Sedin, Bergeron, Couture, Datsyuk, M. Richards, to name a few), he is a middling, 2nd line center, at this point, and certainly this season.
Now add into that the fact that his points this year have been largely due to circumstance because of his linemates and placement.
I'm not saying he won't have a good future, or become a high end #2/decent 1B, but to act like he's playing anything better then a decent #2 right now is absurd and frankly, incorrect.
Also, you can consider me impressed by your "faith" in him down this coming stretch, as in past seasons, Stepan has done nothing but disappear when the going gets tough, specifically, in the playoffs. I'll reserve my "faith" for his clutchness, when he, you know, actually shows it for once.
I like the guy, but god is he overrated here. A #1C, please.