Jimmy Watkins used a Wattbike in his training leading up to the Olympics.
Blog Post - Wattbike UK
Blog Post - Wattbike UK
I've seen photos of Sarah Hammer using one. Not sure if they were promo shots or if it was actually an integral part of her program.
I trained on Cycleops bikes for a season with great results (even as a sprinter). I didn't lift weights that season and my on-bike strength and power went up. But, that was due to having a great program written by my coach.
http://www.cycleops.com/products/indoor-cycles.html
So, I
definitely think you can achieve any goals you want using a Wattbike. What to do on the Wattbike is a BIG question. Most "spin bike" workouts aren't track-specific, meaning that they may not train the energy systems in the way that you need to at the particular time of year that you need to train those things...basically "Programming".
If you want, I can recommend a world-level coach that specializes in training his athletes with spin bikes.