Actually, don't call it a comeback, they been here for years. There are rarely, if ever, any bluechippers going to Mid American Conference programs out of high school and its schools don't often get more than a couple of guys drafted in the first couple rounds of the draft each year. However, if you look around the league, there is an rather high number (relatively) of MAC grads (or non-grads) considered elite at their positions.
This is just off the top of my head because I couldn't find a recently updated list of MAC Alums in the NFL. VanDelay Sports has the best one, but it appears to be at least five years old.
QB- Ben Roetherlisberger, Steelers (Miami)
RB- Michael Turner, Falcons (Northern Illinois)
WR- Greg Jennings, Packers (Western Michigan)
DE- James Harrison, Steelers (Kent State)
TE- Antonio Gates, Chargers (Kent State)
PR- Josh Cribbs, Browns (Kent State)
There are also a few guys in recent memory who were among the top at their position such as:
DE- Jason Taylor, Dolphins (Akron)
WR- Randy Moss, Patriots/Vikings/etc. (Marshall)
CB- Asante Samuel, Patriots/Eagles (Central Florida)