Pretty simple, really.
Given the personnel replacements that have to be made (and so many of you seem to be missing the point on how difficult it's going to be to replace both Todd and Tate) the metric to judge his progress should be fairly simple.
1) Maintain the level. If he can avoid a significant dip (two or three games) that's going to be a bigger achievement than winning eight this year. If he can follow up this recruiting class with another that addresses needs (more so than racking stars) that will also be a win.
2) Fix the motherfucking defense. Make all the excuses you want, but we've been thinner, we've had fewer playmakers, we've played tougher schedules. We've never, ever, ever, ever ever fielded a worse defense than this one. Ever. That is absolutely unacceptable. I don't care what else Auburn does, but we better by damn play defense. There's no reason for a team helmed by a defensive-minded coach, as he's supposed to be, to be that fucking awful. We proved (against an admittedly stagnant and much overrated Alabama offense) that we are capable of better.
3) Answer special teams questions. You shouldn't be still trying new guys out in the last two games of the season. Find somebody who can make decent decisions, has a little speed and then drill his ass over and over and over until he understands that fumbling the ball means that the next thing Nova gets to chase in pre-game is his scrotum.