From my research it would appear that in sports like swimming, biking, and running - provided an athlete is blessed with, or has trained a high muscle specific oxygen uptake capacity, then the limiter to maximal aerobic performance appears to be central VO2max, particularly cardiac output.
My understanding is that VO2max is a corralary (sp) and not a cause of high aerobic performance. It's not how much oxegen you take in it's what you do with it that counts. I think the limiting factors are much more likely to be capillary, mitochondia density, and the efficiency of the neuro muscular conections. Another point is that VO2max is not even an indicator of high performance it's the % of VO2max that your AT sits at that is the more meaningful number. I seem to remember the power running site has a bit to say about this if you have'nt already checked it out I highly recomend it.
BTW I have no idea who you are, whats your background?