The item Mitch would love to see under his tree is the Korg Little Bits Synth Kit.
littleBits have collaboarted with Korg and succeeded in demystifying a traditional analog synthesizer, making it super easy for novices and experts alike to create music. This little beauty connects to speakers, computers and headphones; can be used to make your own instruments and fits into the littleBits modular system for infinite combos of audio, visual and sensory experiences. Check out the man Reggie Watts showing us how much fun one person can have with this:
Mitch wants it because
“It's like Synths meets Lego meets Awesome”