I actually made the very beginnings of an app like this last winter, but gave up once I learned about Trainerroad and went back to the other project I've got going. I did a couple computrainer races this winter, and I couldn't believe how awful the software was when you're talking about a $1k piece of equipment. Congratulations on pulling through and getting a polished-looking product out.
The goals I'd have for something like this:
-Any kind of multiplayer
-Online handicapped multiplayer - all the tactics and exercise of road-racing, without the bike damage when you crash. Handicapping could be based on each rider's FTP, though that'd require a server to keep track of people's FTP since lying would be an easy way to win.
-Real routes. You could maybe use the google elevation data and google earth textures, and elaborate with randomly-placed trees or something to do it on the cheap.
The video of 0.5 looks amazing. I echo the "shut up and take my money now" folks. I made a little java interval app last winter too, but yours is pretty and has all the power readouts and I want it now.
Online multiplayer is a whole bag of worms that I'll be waiting to implement. Local multiplayer with 2 people in the same room will be implemented soon....and I think I could probably up that to 4 per USB stick pretty easily for training studio use. You touch on one of the problems with multiplayer...with dozens of trainers out there, it's pretty easy for any user to modify their coefficients for speed->power and dominate, or simply lie about what trainer they have. I personally feel that a lot of riders just wanna hop on, get their workout done with the least boredom, and get off the trainer ASAP. Multiplayer gets more into the "game" aspect of things, so it'd be something I implement later. Considering I'm the sole user, it's low on the list at the moment.
I do like the idea of real routes, and had looked at data google has for use, but wasn't that impressed. More courses will be coming soon, but they'll be abstract like what I've got now, and based more on themes like "tropical island", "snowy forest", etc. Scenes are created programatically right now...randomly generated to a certain extent.
Others have mentioned to not worry about the steering. Don't worry guys, 90% of the time I don't use my steering joystick. Your bike ends up being totally controlled by the computer along the path if the controller isnt plugged in. I generally don't want to deal with steering during my workouts anyway. The AI's (and your own rider) do appear to "draft" and then slowly pass on the left automatically, altho there are admittedly quite a few things left to be desired in my AI programming.
There's a certain "fun" element that still isn't totally there, and the AI racers have helped, but I think ghost riders of past performances will help. This app also of course can be run in a "slim" mode so you can just run it next to netflix on your desktop or whatever. Sometimes you just wanna watch a movie or tv show, ya know?