Infendo has a writeup on the possibilities of Dreamcast games coming to the Wii’s Virtual Console. They discuss what Nintendo would need to do in order to accomodate Dreamcast games on the Wii. The storage issue would definitely need to be addressed and licensing is a big issue.

I, personally, liked a lot of the games on the Dreamcast. Sonic Adventure and Virtua Tennis consumed many a day for me when the Dreamcast first came out.

Source: Infendo