I think it's Johnson, for the record. But I caution people against saying Johnson is "proven", based on his play at Michigan any more than Stralman is "proven" based on his play in the SEL. At the very worst, that would be a wash. In more realistic terms, it's harder to have success in the SEL as a defenseman than it is to have success in the NCAA as a defenseman.
Way too early to call, but if we're going on pure talent alone it would have to be Jack Johnson to any unbiased observer. From what I have heard of Stralman, as i've not seen him, he is a very heady defenseman and I like that aspect of his game if those reports are true. That would bode well for future success, but I wouldn't jump the gun here.
Both guys are equally unproven and both guys are equally hyped. One because of his high draft position, great performance in the NCAA, and impressive physical skills. One because of his FAST emergence, great performance in the SEL, and impressive smarts with the puck and Lidstrom comparisons.