Among other things you can do with them (like experimenting with savegames, etc.). You can also use the device.cert to test certain things under SNEEK, but you'd still have to wait for the new version to be available.
However, you *should* be able to use it with an emulated NAND on a real Wii to download the channels you transferred to your vWii, as long as both consoles are from the same region.
good to know, i will be dumping mine then since i would love the ability to download channels that i transferred to my Wii U since i got a couple VC games since the move. since i have a NAND backup and bootmii/boot2, is there any way i could use it with my real NAND or will the Wii not like that? thats assuming it works at all since you mentioned it *should* work. I will give the emunand a try first then post back if it worked at all.
if not,i will stick to the UNEEK+DI emu nand i setup a while back.