Pippen and Prince aren't remotely similar in ability. It's like saying "talk of <player> becoming the next Jordan or Jason Richardson is way too premature." Prince wasn't anywhere near Pippen in ability or value and Batum already isn't far from Prince. Prince was never a star. He was, at his prime, an excellent complementary player. Batum lacks the consistency (which, I agree, is due to aggressiveness) that a prime Prince had...but he's only 21. I don't think it's at all premature to project at least a Prince-like prime (which is still 5-6 years away). Comparing him to Pippen is certainly very premature and I think there's close to no chance he'll ever be that valuable...but an (IMO) top-25 player of all-time is a high bar. I think Batum is likely to approximate someone like Gerald Wallace (but with better health) in his prime. He doesn't have a similar frame to Pippen...Pippen had significantly more muscle to his frame. And the similarities don't end there. He has the possibility of being a point forward (as evidenced by him replacing Tony Parker at point guard for the French team, and by his passing skills in the NBA), he has the ability to slash and shoot that both guys had, he has the uber-athleticism of Pippen and he has the great defensive versatility that both guys showed (Pippen much more so, of course).
What is impressive and valuable about Batum is that he doesn't need the ball to be effective. You don't have to involve him in your offense and he can still make a huge impact. I see him more like a Kirilenko with a jump shot. He's more likely to end up with the quintuple quintuple (points, rebounds, steals, assists, blocks) than be a Pippen-type that puts up 16-20 ppg. He just allows everyone else on the court to be a better player.