Kalengkong,
AFAIK = As Far As I Know. The 5W beasts are actually in production, by the modders in the homebuilt and modifiers forum. If the CPF is the leading edge, the modders forum of the CPF is the bleading edge!
Luxeon life for the 5W whites is 1,000 hours... rumor has it that it will increase this year to 10,000 or 100,000 hours. The modders will then just switch out the lower life ones for the longer life ones when available.
When the long life ones become available, Surefire or Arc will be on it. For now, look at the mod forum.
If there isn't a 5W Luxeon example at SHOT show running on 2x123 cells I would be totally amazed! As to when the pipeline will start to flow......................
Not quite sure the power requirments, but will we ever see a 5W White, in a flashlight the size of a avg 2 cell 123? Is that even enough power to operate a 5W?
I would say ARC will probably have one to market first. AFAIK the 5W will need 7-7.5V so i would think that 2 123's would work with a bit of a step-up converter(similer to ARC AAA). That or go with 3 123's and a resistor.