First, I never heard of this device, it seems very fake to me. There is no link to any manufacturers webpage, not even the name is mentioned, and no link to a shop that supposed to sell these devices.

Second, even if it existed it would still need drivers. Will it support the N900 and linux in general, maybe, maybe not?
And third even the fastest current BT implementation is just 3mbit/s, that is a third of USB 1.1 speeds. So it would be way to slow for a DVB-T USB dongle (my personal goal), that requires USB 2.0 speeds in most cases, depending on the transmitted bitrates.
So no, it isn't an option for my goals