On reflection I think Will and David are spot-on about classic racing at the TT, whichever way you look at it, it would almost certainly be detrimental to the MGP and play havoc with practice and race schedules. Good point guys.
In terms of the field depletion issue (which I know isn't strictly on-topic but has been discussed at length) there is no way we can blame quick riders for that. People have always been fast on fast bikes. To my mind it's 100% the TT course licence requirements. Look at the entry for the Senior Classic - we had 105 bikes in 2005 (anyone remember the Belgian bloke with the Paton who was number 105) and, after the 6 races-a-year rule came in, the entry dropped to 90 in 2006, 69 last year but happily has recovered slightly to 73. The same trend, as everyone knows, is evidenced in the Junior and the Lightweight and it's a big shame.