I've been testing everything possible. I tried to power my gp2x wiz off of my 43IT...the charging light kinda flickered for a second or two and that was that. I also hooked up my wireless keyboard with a trackball. Keyboard works fine, but has the same problem my bluetooth keyboard does in portrait mode: the arrow keys. However, much to my surprise, the volume adjustment and the trackball worked flawlessly. I also took my IOgear card reader to it which also worked just fine.
I was honestly very confused by all the talk of micro A or B in the forums and just took a total shot in the dark on this cable, but it works like a charm! Got two just in case something happens to one.
Hopes this helps someone.