It has always been important to peak at the right time. Early season losses have always been easier to overcome than late season losses. A 4 team playoff didn't really change any of that. But, as many of you have pointed out, as more teams are added to the playoff pool, less value will be placed on individual regular season games. Remember, a 2 loss LSU team won the BCS title a few years back, so even that has always been possible under the right circumstances.
I don't see teams with more than 2 losses making into an 8 team pool, so I don't have a problem with that number. My preference would be a field of 6, with the top two seeds getting a bye in week one. It forces teams to try to land one of those two top spots to avoid a third playoff game - placing real value on all regular season games again.
But, no matter what method we use to crown a champion, late season performance will always be more important than early season performance.