The real problem is that people expect him to be a 40 goal scorer, when he simply is not (Well that and we expect him to be a goal per game player like he was in the 08 playoffs). It's quite the anomaly. Even Mickey Redmond refers to him as a 40 goal guy, but check his stats, at 33, he's never scored that much. Hell, he's only scored over 30 goals once.
Moral of the story, perhaps people need to change their expectations of how much this guy scores. He's a high 20 goal scorer. Couple that with an average of 20 assists and it doesn't seem as bad as people make it out to be.
I do think he will largely benefit from playing with workhorses like Weiss or Alfie though. Guys who aren't afraid to get a little dirty while he gets himself into prime scoring positions (and when you can shoot the puck like him, that's pretty much anywhere).
I'm not so sure it's Franzen's production that people have a gripe about. At least for me personally, it's more the appearance that Franzen doesn't show up to play every game. He is a great value for the contract, but that doesn't make floating and lack of effort acceptable. Franzen's massive playoff years probably skewed some expectations, though in reality Franzen hasn't performed at all in the playoffs since then. So, when your fallback is "playoff performer" and then you don't do that anymore -- combined with the floating during the regular season, that's where fans start to get upset with Franzen.
I agree that Weiss centering a line should help out Franzen this season. He needs somebody to do most of the work.