
Octal tipped us off about the new PIC12LF1840T48A microcontrollers that have a built in sub-GHz transmitter:
Microchip just published the datasheet related to using the PIC12LF1840T48A Microcontroller with Integrated Sub-GHz Trasmitter.
The PIC12LF1840T48A is a Microchip microcontroller that has an on-board transmitter. The transmitter is suitable for operation in the 418, 434 and 868 MHz license-free ISM bands.
Via the forum.

(sigh) no love for the 915MHz-ers
Great! I hope there would be an equivalent receiver MCU, probably PIC12LF1840R48A, coming soon.
Even better if they could build a PIC with a transceiver on it. like PIC12LF1840TR48A :D
*This pic also has a comparator on board and a low freq/low range reciver could be built like in the app note we posted about the rfPIC12F675
http://dangerousprototypes.com/2011/11/20/app-note-tire-pressure-monitoring-system/
If it doesn’t *have* to be a PIC, consider the Si1000; it has the transceiver, also more flash & RAM.