The only faux pas: Arriving late to a two-party format war that consumers are already reluctant to support.Next month, New Medium Enterprises' 1080p set-top players, which use the HD VMD (Versatile Multilayer Disc) format, will go on sale on Amazon.com and in stores such as Radio Shack and Costco for around $150--about half the cost of the least-expensive 1080p HD DVD player, and perhaps a fourth