I would very much like Bluetooth but for file transfer with 'phones and PDAs, not for wireless peripherals. The file transfer would be a genuinely new capability for RISC OS. For me, that would need to be a USB Bluetooth 'dongle' as I'd want it on my Iyonix.
I'm not personally convinced of the need for wireless keyboards and mice on conventional computers - the wires don't bother me whilst batteries and RF (with its privacy/security and interference issues) seem too high a penalty. Set-top boxes and the like that will be in non-traditional (for a computer) locations are a different matter, of course. On that note, I see that Apple are now bundling a remote control with their Mac Mini, presumably in a bid to capture some DVD player (and PVR etc) market-share.