In the over-simplified world of sports journalism or Internet hockey message board-fandom, Marc-Andre Fleury is now an elite goalie. If Chris Osgood had stopped both of Maxime Talbot's shots in game 7, however, then Fleury would not be elite (and by similar logic, Osgood would then be deserving of being immortalized as one of the 30 or so best goalies in the history of hockey). Such is the narrow margin of what constitutes "eliteness".
Is Marc-Andre Fleury actually one of the very few best goalies in the NHL today? I don't think so. He played very well in games 6 and 7 of the Stanley Cup Finals, but I don't think he was that terrific in the postseason as a whole. In fact, Fleury quite likely had the worst overall playoff season of any Stanley Cup winning goalie in the last decade (.908 save percentage), so it seems a bit curious to me to suddenly claim him to be one of the league's best, no matter how spectacular he was stoning Lidstrom with seconds left to play in game 7.
Since the lockout, Fleury's save percentage has been .908 overall and .921 at even-strength. League average has been about .906 and .918 respectively. I don't think the Penguins are or have been a shot quality outlier (except maybe 2005-06), so those numbers probably give a fairly good indication of what Fleury is: An above-average goalie. On a good day, Fleury's athleticism gives him a higher peak than other goalies of his performance range, but he doesn't appear to be a Lundqvist or a Luongo, despite his more impressive jewellery collection.
Fleury is 24 years old, so it is probably reasonable to still expect some improvement. But goalies generally peak earlier than conventional wisdom suggests, and Fleury is likely either just beginning or already in his prime years. He's good enough that most teams would lock him up long-term if they had him, and he will likely give Pittsburgh good goaltending for the next decade or so, but I'm not expecting any Vezina calibre performances (although with Crosby and Malkin up front, the possibility is there for a 45-50 win season that might end up being recognized with some not-necessarily-deserved hardware).