A few thoughts...
I never cared much for Pittman. Apparently, the NFL didn't (doesn't) either. I'd rather have Beanie as the primary back. Was it Dick Tressel who said this year's running back position is the deepest one yet? If Dick didn't say that, then one of the other coaches did. In any case, I'd give the nod to the 2007 team.
The threat of Ginn was as important (if not more important) than Ginn himself. Ginn allowed Gonzo to break loose and make big plays (defenders focused on Ginn, thus leaving Gonzo open). This year's squad has Robiskie and...that's it...so far. At some point, defenses will learn to cover Robiskie, so some other receiver will have to step up the way Gonzo did. Although I really don't like to use the NFL to judge college football...the 2006 team had two first-round WR draft picks. How many does the 2007 team have? 2006 takes it...for now.
The current offensive line seems to play better this year. I attribute this, in part, to the play of the tight ends---particularly Ballard. Ballard has made a few key blocks, which allowed running backs to gain considerable yardage. But is the offensive line really better or is the perceived difference really due to using more tight end sets (which in turn have helped make the o-line look better)? Since this year's squad lacks solid depth, I'd take last year's o-line.
Quarterback: The threat factor applies here as well. The threat of Smith running had to be taken seriously. So much so, that a defender would be assigned to "spy" on Smith. This threat (along with the Ginn threat) allowed someone on the offense to be open. Boeckman doesn't create that running threat, but has shown an ability to throw a pretty good deep ball. I know, I know...Boeckman's stats indicate a high number of INTs. At least 3 of those can be attributed to great plays by defenders. The 2006 team had better depth. Pick: 2006, but not by much.
Special Teams - 2006 (especially given the kickoff rule change), but I really, really like what I see in freshman Brian Rolle on kickoff coverage.
Defense - 2007 in every aspect. Seriously.
Now here's the best part about this 2007 team. Virtually the entire team returns next year!
Losses due to graduation = Kirk Barton (that hurts), Fullbacks (not a big deal, imo), and Larry Grant (plenty of good players behind him).
Losses due to the draft = speculation. Robiskie, Laurinaitis, and Jenkins have enough talent and promise to bolt for the draft. I'm not sure Boone or Gholston have made a big enough impact to be chosen high enough to warrant leaving, but you never know (ie Pittman).