blue tooth and bulit in reciver?

hi there can some one tell me what the differnce is between my, mitac mio 168 which has a built in reciver, and blue tooth?
reason that i ask is because i have been waiting for the undate but it seems to have not come out yet, is this because tomtom 5 for the mitac mio is not worth there while rushing it to the shops to buy the upgrade?
or is blue tooth the best?

thanks for now.