Samsung has abandoned their newest combo rig, LG says they will continues to support both formats for a long time, but hard to say.
There is about 1 million hd-dvd settop players and maybe the add ons in US home, maybe it's world wide, but it is probably enough to make it worth while to produce a small scale run of combo units for a while, especially if your the only game in town.
I'd watch the demo/clearance sales and get a BD player cheap if possible, unless you just want to stick with PC based drives, then it's the LG combo, either reader only or BD burner/Hd reader. Hopefully the price will come down. Friend who builds systems said he picked up the burner version through one of his suppliers for 325 US, dealer cost I'm sure.