I've been following sportscar racing since the early 80's, and researched it another 10 years prior to that. Stepping back from it all from the past 35 some odd years shows a distinct rise and fall, in a 10-12 year cycle..

early 70's -early 80's Group 4/5/6
early 80's-early/mid 90's Group B/C
mid 90's-present LMP/GT (with some mods along the way)

Has the current formula lived long enough? Is it time for change? The interest is certainly still there, at least from a Le Mans perspective (more entries than grid spots year after year). FIA GT is stable, and the LMES looked good in 2006 as well. ALMS is facing 2007 grids in the low 20's (or less, perhaps), but the quality is strong...

What's your thoughts? Propose a new structure if you have ideas....