There is an application called "bluemaemo" in extra-devel. I tested it with powerpoint with a generic bluetooth usb dongle on my windows7 machine and it works just fine. There are several profiles for different programs to use remotly (winamp,powerpoint etc.) . Even the mouse or the keyboard can be replaced with the n900.
Unfortunately my usb-bt-dongle only works well with a bt-stack provided by a Software called "BlueSoleil", so if the services of N900 are not detected try this one.

greetings,
ein_guter