Philip Rivers is currently 20th all time in passing, and he's only 33 years old. If he plays into his late 30s he'd easily make the top 10. He's also a legitimately great QB who can beat anyone. When he had a defense and a running game, the Chargers were the best team in the AFC.
Brees is a slam dunk for the HoF. He is 4th on the all time passing list and climbing. And he won a SB.
Rodgers is well on his way to the HoF.
They've been saving a spot in Canton for Andrew Luck since he was in the 8th grade.
Russell is probably in unless his career completely tanks somewhat soon.
Big Ben gets in.
Eli is probably in, unfortunately. He is the least deserving but he did win two SBs, and I think there will be a 2004 draft narrative that will help all those guys (Rivers, Big Ben, Eli) get in. Remember, the guys that do the voting are narrative whores.
Tony Romo could be an interesting one if he wins a SB in the next few years. Right now I'd say no way in hell, but him getting a ring and maybe finishing his career over 40,000 yards, in Dallas, would probably get him over the hump.
Matt Ryan isn't HoF caliber IMO, but he puts up great numbers. Could be a Dan Marino type if he lasts a long time.