To touch on the Kesler vs. Higgins topic: MS makes the most important point in this debate - Higgins' "high" offensive potential is lowered in my eyes because of the doubt in his ability to transfer his skills to the AHL. Kesler might not have the greatest puck skills or playmaking ability, but he is talented enough to either put up points as a top end shutdown guy or be the workhorse on an offensive line. I'm not going to even begin to make a choice as to who is the better prospect (not seen enough of Higgins), I'm simply pointing out that the difference in offensive potential people like to think exists between Higgins and Kesler is perhaps a bit exaggerated, in my opinion at least.
In general, I'm not comfortable comparing prospects because I don't have enough first hand experience watching most guys, but I do see a LOT of WHL. Having said that, Coburn is in my opinion better than Barker. Barker has a much higher offensive potential, but Coburn is the far more well rounded player. He has good puck skills, he's very mobile, huge, very strong, and has excellent positioning, but most of all, he just does everything right. Barker has better offensive instincts, but he's not particularly good in his own zone, makes more mistakes, and doesn't seem to have the same intensity as Coburn. The one thing I'd like to see more from Coburn is physical play (use that monstrous frame!), but that's true of Barker as well. Barker has a higher ceiling, but he's less likely to reach that ceiling than Coburn.
Another WHL defenseman who doesn't get enough recognition is Shea Weber. This is a guy who has gone from a possible 5/6 guy two years ago to someone who should become a top 4 defenseman. His offense has exploded since last year's playoffs, showing that he has the skill and shot to be more than just a physical presence. He's big, EXTREMELY physical, a very good if not blazingly fast skater, an excellent hitter, a decent passer, he has a good (right handed) shot, and his positioning and hockey sense are outstanding. If he can translate his offensive game to the NHL and become a second unit PP QB, he could be a #3 guy; if not, he's at worst a #5 that makes opposition forwards keep their heads up. I have no idea if he'd fit on a top 50 list (probably not), but in comparison with some other WHL defense prospects, I'd have him way ahead of guys like Green, Shultz, Fistric and Belle, ahead of Meszaros, and only a bit behind Seabrook. Also, having seen a lot of Koltsov, I'd have Weber WAY ahead of him, but then again, I'm not a big fan of Koltsov. Judging by where people I am familiar with are expected to be, I'd say Weber fits somewhere between 50 and 70.