I think it is a bit early to predict any of this... It will be interesting to watch, but at this point in time it is very premature.
I'd have to wager that Kessel probably still has the most individual scoring talent (and offensive tools beyond assists) and should be able to demonstrate that. The only question I still have is whether or not he will be able to do anything to help anyone else on his line.
While Backstrom could conceivably put up some decent numbers in the NHL next season, I really think if he is here, the Caps will look to work in defensive responsibility first and foremost. Then after he gets that down, turn him loose. As far as production, if he plays healthy minutes on Ovey's line by the end of the season, he'd probably end up with something like 10 goals and 30 assists, and I'd be more than happy with that type of year. I'd hope for more, but really I think the Caps will move slowly with him and increase his minutes down the road and in the latter parts of the season.
As for Jaded-fan's admirable glass half full, lets at least wait until all three players put on the skates. I mean, the team wasn't able to do anything with a little Mario, a little Palffy, an aging Leclair, some Recchi and Sidney (plus no defense) what is to say 3 young kids can carry the team to a winning record now. I think that Staal, Crosby and Malkin are going to be solid NHLers (and maybe 2 of the best in the game out of the 3) but they won't be such from day one (at least definitely not in Staals case). Similarly, what is to suggest that they're ready to dominate right away where other players with solid talent levels who were NHL vets, weren't able to do it. I equate a lot of the Pens situation to a certain NFL football situation up the road from Pittsburgh. The Detroit Lions took 3 quality reciever prospects, all top draft picks, and some suggested to be some of the best in the game. You have to build something else around them. Having 3 #1 centermen might be a luxury, but I don't see how you could logically pay all 3 when you have a absolute hole at defense. Maybe Staal can play some defense. Maybe not. It will be fun to watch the 7-5, 6-3 games, but with ol' Gonch and the rest of the Ole' defensive corps up there, I wouldn't expect to be lifting the cup this next year. While today is a good day to enjoy the draft and picking up Staal, I really think in the future you need to pray that your team one, builds a new stadium or works a deal (or you'll be seeing those riches play in Kansas City or some other town), and two finds some solid defensemen who play for cheap, because in 3-4 years time when your team gets good, you'll have 16-17 million sunk down the middle on 3 players (and probably another 4-5 on MAF if he turns out to be worth anything).