It's really not.
1) Fleury
2) Bylsma
3) 4th line
4) Health
5) Orpik/Letang... Engelland on defense
All bigger concerns. You can argue opinion, but Jesus, there are way more serious problems than Jokinen on Malkin's wing. The third line is a massive concern too, Conner/Ebbett/Kobasew possibly on wing no matter what is a serious problem; God only knows what happens to Crosby's line. Malkin's line won't be worth **** with those problems, those problems don't get overcome by one line.
I'm going to agree with Kirk on this one. Tbh, IF Jokinen can keep the same level of production he has now going in the playoffs, then perhaps he won't be such a big concern. But the eyeball test says that he won't be winning pucks for his linemates, won't be crashing the net or screening the goalie, and his faceoff skills have deteriorated to boot.
So Jokinen is going to be useless against a physical, defensive team like the Bruins, and drag two of the Penguins' biggest weapons down with him.
This is why I too am hoping against hope for a Kulemin trade, even if it costs a decent prospect. Can't waste your top guns' prime years like this, IMO. Also, your issues #1,2,4 and 5 can't (or more appropriately, will for 100% not) be dealt with via trade etc. And issue #3, the fourth line, pales in comparison to having your second line geared for the playoffs.