The desktop guitar amp is a great idea that has yet to find it’s ideal form factor and price point. A few friends and I have seen, played and returned or Craigslisted many in a search for small sonic delight. A few of the more interesting ones were the Vox JamVox (nice software), the Zoom ZFX (cool case), the Fender G-DEC series (backing tracks galore).
Yamaha enters the fray with the THR-10, part practice amp, part USB audio device and part nightlight. Yamaha want this to be your “third amp.” Check out this comprehensive demonstration and interview with by Yamaha Product Specialist Julian Ward.
This looks like a fun little amp and I am anxious to add it to my list of amps tried. The good news is that the Yamaha web site says “Available in January 2012.” The bad news is that I am writing this in March of 2012, and the few on-line dealers who list them still say “Coming Soon.” Apparently this is due to a problematic power supply in prototypes and early models.