I don't think FIRST needs to provide a bonus, but rather I encourage programmers to each get a test chassis from their teams, and create robots that can auto aim, lead aim, and perform obstacle detection.
The teams that have auto aiming tend to do the best in many competitions. 469 has been praised for their loop hole robot, but I think one of the most impressive aspects, was the robots ability to actually play the game. Almost entirely due to one of the fastest auto aims I've seen.
http://www.youtube.com/watch?v=FA0FSXlvf_Q
I know my team, 319, had our auto aim to thank for the success in 2006.
And trust me, drivers being proud and confident in their abilities, will always claim to not need the auto aim. At the end of the day, if your robot can auto aim they will use it.
Autonomous used to be a much more exciting time period, and based on FIRST's choices for autonomous post-2006 I don't think we can count on a exciting one. If you look at 2003, 2004, and 2006 they were all very impressive autonomous years with huge advantages for robots with a good autonomous. Interesting too, they were exciting not only because of points, but the spectator aspect. Spectators love to see robots score, they get bored fast with low scoring matches. So who knows, maybe we're overdue for a strong autonomous incentive again.
I sure hope so...