An 8 team tournament, with conference champions participating only, would highlight and preserve the importance of the regular season. Win your conference or stay home (or go to a bowl game), no wild cards. It would eliminate the possibility of a team that didn't even win its own conference playing for the national championship.
It's said that every game is a playoff game in college football, but you can win all of your games and still not play for the national championship. At least under the old system, the #3 team still had a chance, if #1 and #2 lost their bowl games.
Changes to national championships aren't anything new. Prior to the 30's, it was a wild west, with pretty much anyone able to hand one out. Then we had the polls, after the season, but before the bowl games. Then we had the polls after the bowl games, which turned the bowl games from a glorified exhibition game into the key game of the season. Then we had the BCS, which matched #1 and #2, but left out teams that had a legitimate claim to be the best.
People talk about preserving the value of the regular season, and to do that, we need an 8 team playoff. Opening round at the higher seeded team's home site, this would give added incentive to keep playing hard. Losses would drop a team's seeding, or drop them out of the tournament altogether - in an 8 team tournament, if there are more than 8 conferences, then only the top 8 champions go.