HD game of the week, a one hour broadcast, will show up on a separate channel from the 24/7 NFL Network channel which is SD.
DirectTV probably has several options for this.
I don't think Dish has announced it will carry NFL Network-- please correct me if I'm wrong.
A cable provider with InHD/InHD2 (if any are carrying NFL Network), could pre-empt the regular InHD2 programming and put the NFL show on there (I think), since this can be done with regional HD sporting events.
I don't know what a cable provider without InHD2 would do, other than create a special channel just for the NFL HD show (and any other special HD events, like the NBA HD games, Masters golf, US Open Tennis, etc.)
NFL Network has an uphill road getting carried on cable. With the NFL giving exclusive Sunday Ticket rights to D*, cable providers probably won't carry it until they have some contractual commitment that, when D*'s current exclusivity right expires, the NFL will not enter into any further exclusivity agreements.
Maybe if NFL offered this network for free (no per subscriber fee) it might get carried on a significant number of cable systems, but barring that I would be surprised if any major cable operators carried it before Fall 2004.