It's hard to know with guys like Pajuniemi because the offense is predicated on finding time and space. Even if you put everyone on the same-sized sheet of ice, there's nothing that compares to the speed of the NHL. If you're going to be a guy who lives and dies on finding soft spots to fire one-timers and things like that, you gotta be damn good, have excellent hockey sense, and the ability to see plays developing. If you can't do that, you won't find the creases and seams, or if you don't you won't find them quickly enough to shoot. And then you're Ryan Gropp, a mediocre AHL player.
You also need to make an impact fairly quickly so you can earn some PP time. Guys like Pajuniemi will thrive on the PP, but they have to get there first. Half his goals last year were on the PP. But stepping into the NHL, unless you're a really special player or are breaking in on a horrible team, you're not generally gifted PP time. So he's going to have to improve his 200-foot game (which he has done, somewhat) and learn to do the small things so you can hang around and make enough of an impact to get that coveted PP time.