I've got a Kensington Scroll Mouse but it stopped working for some reason. I think it's a driver issue. Gotta sort that out because I love that thing. :-)

If you don't have a touch screen, you cannot use touch on the screen. Obviously any other HID will work, including presumably mousepads with multitouch.
 
On the other hand, if you purchase a device with Win8 on it, it's likely it will have a touch screen.
 
I mourn the passing of cabled Logitec trackballs. I keep forgetting to take that silly RF dongle out of laptops.

 
Absolutely AT!!! Make it a little larger than an i-pad, perhaps a 15" screen with a flip out stand on the back to just lift it to a mild angle, plenty of rubber around the back to hold it still. Whoever does it, I hope they pull out all the stops and make it right. The imagination flies....
 
J

Or buy the Microsoft Surface Pro tablet when it arrives in January. http://www.readwriteweb.com/enterprise/2012/06/why-microsofts-surface-pro-will-be-the-first-real-business-tablet.php

Dell ST2220T, 22" Touch TFT, HDMI, FULL HD
Eizo T2351W, 23" 16:9 Multi-Touchscreen,
Hyundai G75TR Touchscreen, 17" TFT, DVI-D
Acer T231H, 23" 16:9 Multi-Touchscreen

and, if money is no object,

Samsung SyncMaster 460TS-3, 46"!

There's quite a choice out there already.

none of the above suggestions include a motorized fader - I don't think touchscreen faders work very well and certainly miss something tactilily.

Plus there is the automatic assignment I'm hoping for - use your left hand to select a a channel and the fader is automatically assigned.  No muss, no fuss.

@

I'm curious. Does anybody make QWERTY keyboards with MIDI assignable controls? Like maybe a row of knobs and basic transport buttons at the top? That would be cool. Full on sliders might be a little too much for a keyboard but those parameters could be controlled by the knobs. Or maybe some mini scroll wheels or toggles.

I don't see why it couldn't work well for fine adjustments. Picture it: you touch a knob and slide your finger up or down. The speed at which you slide it determines the rate of adjustment. 

I bought a 23" touchscreen monitor about a year ago to try to use with sonar and plugins to alleviate my wrist issues caused by leaning on the mouse all day.
I don't use it because the results were inconsistent-  some knobs and faders were smooth and controllable, others were jumpy and imposssible.  The pro channel was not touch friendly, but the cake brand vocal strip and other plugs were very touch friendly.

In the end, I figured I'd just have to wait for the technology to improve and for the developers at cake to fullly implement what windows 7 and 8 have made possible. (touch-wise)

I still use the monitor everyday- i just don't touch it.  I will be thrilled if I can make use of it with sonar when X2 comes out!!!!!!

btw- i like the idea of selecting with one hand and adjusting with a single fader and knob.
Even with a working touch screen, i will still keep my Mackie MCU Pro and C4

Beepster,

not that I know of.  However, there was a keyboard/computer w/ a little (4 inches or so) touchscreen imbedded to the right on it).  I can't remember the details.

@

One of these to use with the matrix:

http://www.mimomonitors.com/

http://www.wholesale-star.com/portable-7-inch-usb-powered-touchscreen-monitor-p-1123.html 

Touch-monitors: Lots to use them for. Lots to not use them for.