OpenPicus is working on open source wireless hardware and a free application development platform. The current WIFI hardware has a PIC 24FJ256GA106 microcontroller, and an MRF24WB0MA module provides the wireless.
An Arduino-like IDE has libraries and frameworks to simplify wireless development. If you have the grit to develop a wireless app without a proper debugging tool, then the firmware can be updated over USB via a bootloader in the PIC.
They sent a press release through the contact form. We asked for a sample, and got one. After we test it we’ll give it away in the comments.