Obviously I'm biased and he's playing miserably right now, so the sentiment is probably laughable at the moment, but the intrigue of Pettersson's potential from his rookie season has been that he had the natural talent to be the most gifted-at-both-ends player since Fedorov (since his concussions/injuries/general complexities though, maybe not possible anymore). His top speed was never quite Fedorov level, but at one point, had the ability to win the hardest shot, was more than Selke-capable defensively when playing well (should have won that one year), and was able to get 100+ points (even after injuries limited his offensive skills somewhat-- his peak year was more about playing within his new limitations and relying on offensive IQ/instincts rather than the raw skill that he showed earlier in his career).
Would be an unlikely miracle for any of that to come to fruition now, though.