Since the Wiimotes use bluetooth(and there isn't any other interesting hardware in the system), I was under the impression that most of the homebrew community was just syncing them to PC's rather than really trying to hack the Wii.
Besides that, there's a couple fun homebrew games, mainly ports of emulators and games that you could also play elsewhere.
I've used these exploits, along with an external drive formatted to wbfs and used as a "backup drive". (Read as piracy storage)
Ive played the emulators on Wii, as well as video players. They stink because of excessive lag, even mplayer. If there were cool things one could do with a Wii, Id like to see them. Aside from Wiimote Blackboard and other controller apps, its a rather unimpressive boring system.
So its back to piracy.. and cheating.
A real computer with hdmi out can play everything. And one of the cheapest hdmi laptops are $300.
And what's with the downvotes? Am I functionally wrong with my assessment that there's nothing spectacular with this console? It cant even do HD, let alone play DVDs (yes, earlier versions could, but has been disabled in hardware).
Most of the Wii-based media "solutions" are more easily (and better) handled with an old laptop (or cheap new one) and a bluetooth dongle.
I don't think I own enough Wii games (around 20 just now) to justify buying an external drive for ripping purposes, and I can't really see that changing.
The emus always worked well for me, though.