It looks like modular synthesizers are in this fall, with the Patchblocks project launched recently on kickstarter.
These differ from the littleBits KORG kit we introduced earlier this week in how they function.While littleBits focussed on creating a standalone KORG synthesizer, Patchblocks are programmable modules that can be linked together. If you want one block to control pitch while the other serves as a filter, you simply transfer the software from your computer. Connecting the Patchblocks in a different order will control the signal flow, and which module process the signal first. They also sound really cool.