I kinda agree with tired guest. The place where ID'ers can have a real impact on bicycles is in the componentry. Take a look at the latest Bontrager aero brake-levers. Very nicely done, but are functional and aerodynamic. For a frame, by all means function over form. There are a lot of very pretty frames out there, but many of those pretty carbon frames aren't any better (vertically compliant, stable, laterally stiff, etc.) than something with straight carbon tubes. Take a look at the Madone for instance. I'm not crazy about the seatstays, but I don't question the actual function of the frame. I've seen the evidence and it is, in fact, superior to the older 5000 series frames.
Getting back to the UCI part, the reason they brought out the rules regarding double-triangle frames is because they wanted a level playing field. In the late 90's, it was exciting to watch the Tour prologue for the simple reason that you would see a lot of crazy carbon bikes, many that were over $10K. Bjarne Riis is known for his spectacular bike-toss of a TT bike in '97. Maybe '98. Whatever. The UCI thought it was getting out of control and that lower-budget teams didn't have the same type of equipment. The stars were essentially buying seconds off their TT times. So now we're in the same situation, as innovation never, never stops. The TT bikes out there cost just as much as the wild ones in the 90's. BMC, Trek, Cervelo, etc. All of those frames cost well over $3K.
The UCI has also instigated a rule on bike weight. I think it's around 15.2lbs. Bikes are getting down in that range pretty easily now, so pros are starting to toss in power-meters and all kinds of extra gizmos to get the weight back up. Thank you UCI for killing innovation.