Before:

Championship involved top two teams in BCS standings

After:

Championship involves top four teams selected by Committee.

Before:

One of the G5 teams got one automatic spot under certain requirements in one of 4 non-championship bowls

After:

One of the G5 teams gets one automatic spot no matter what in one of 3 non-semifinal bowls.

So, G5 teams pretty much had no chance at a championship before the playoff and will pretty much have no chance afterwards either. But, they will more access to the "major bowls" outside of the playoff than they had before.