I've tried about every kind of pointing device known to man and nothing has really satisfied me. Most recently, it was the Logitech Cordless Optical Trackman. While it was nice to have all those buttons, the software didn't support application sets, which stinks. So why isn't Kensington getting on the ball? (Pun intended.) Here's what I want, using the Turbo Mouse Pro as the starting point:
1- Optical. They've been making optical mice for a while now and recently introduced the Orbit Optical, so they have the experience. Keep the ball bearing rollers, though, to retain the smoothness of motion; steel or Teflon balls can't match it. Seal the optical window as Logitech does because open windows like Micro$oft's suck dust and pet hair inside.
2- Cordless. Use Bluetooth since it's the new standard. Sell an optional Bluetooth receiver for those of us who don't own the new Powerbooks and the next rev PowerMacs. Although I'm not thrilled with having more batteries to replace.
3- Revised Turboring. Most reviews I've seen of the Turbo Mouse Pro don't like the scroll wheel location. I don't really like a scroll wheel for reptitive scrolling, either. Bring back the Turboring for continuous scrolling but make it more solid than the original. Bonus: it can be used for all sorts of other functions like as a jog wheel for video editing or as a volume control for iTunes. The Griffin Powermate and Contour SpaceShuttle show that people are willing to pay extra for this functionality. Also good for FPS gamers.
4- Optional foot pedal. This would make dragging and drag selecting easier. Much better than wasting a precious button on drag lock. As a bonus, it would appeal to transcriptionists, who currently pay upwards of $70 for USB foot pedals. And it wouldn't be bad for gamers, either, who sometimes have too many buttons and not enough fingers. My $30 el-cheapo USB steering wheel has pedals, so why not a $100 trackball? Bluetooth would be good, too, to use the same receiver.