OP, that is flipping brilliant.
Got me googling for conversion kits and the like. They sell them, but for about $270, without skis. These are basically v shaped triangular bits of metal with axles at the pinnacle. You screw them to an old chopped ski or snowblades. They weight them slightly towards the back so if you get air (yeah right), they automatically tip up a bit at the front to stop them digging in when you land.
Bit more googling got me to this: http://www.bikeforums.net/showthread.php?242516-Ski-Snow-Bikes-is-Done!!!PICS!
They’ve used same concept essentially, but using skateboard trucks to fix the blades to the bike, which seems a good idea.
I have an old pair of snowblades, I reckon if I take off the bindings and screw blocks to them, then fix them to the bike dropouts I’ll be up and running. Well I would, were the snow not to have melted. I wondered about the trucks moving as you angulate, therefore getting it more difficult to dig in an edge when turning?
Think I might give it a go