though i have access to the internet...my xbox doesn't yet....does anyone know if dawnguard will have a disc available or is it strictly gonna be downloadable?

Download only. It'll probably come with some kind of GOTY edition, but that will be at least a year to two years down the line.

You can still access the marketplace without live. It will probably only be put on a single disc, with Skyrim, and all other dlc in a GOYA.

Currently its download only.