I notice this on the link you gave:
Not a PS3 Owner?
Early next year, all players worldwide will get to experience this premier shooter when we releases a Battlefield: Bad Company 2 multiplayer DEMO on the Xbox 360, PS3 and PC.
Looks like it has been delayed. However, I'll look into it.
TBH, when I talked to GvD I picked up a sense of hesitancy in his voice about it. I spoke to Garetjax afterwards and I think we had agreed the DICE team might be struggling with the PC version, given the novelty of bringing the Frostbite engine into the mix.
Thanks for the update.