I seriously doubt they will be selling these at a loss. The hardware itself is claimed to be "two or three" times more powerfull than the gamecube. Since the GC launch in 2001 you can assume the technology for the Wii (which is very similiar IIRC) is a fairly affordable price at this point. The controllers themselves dont seem to contain anything terribly expensive, just an innovative use of two existing technologies.
The only things that may possibly affect this will be the addition of 512 MB built-in flash memory, the possiblity of an additional wiimote and the sensor bar itself. But I dont belive that any of these is a deal breaker on a possible 200$ USD launch price, especially with how weak the USD is currently.