Added truncha question, and changed the twilight hack question. "What's happening now?" Needs to be updated, feel free to do so.
Probably not. Everything we do is erased from memory when you turn off your Wii. Future hacks might be more invasive, which will carry greater risk.
===What if the next Wii update patches the
exploits?===The only ways to "patch the exploits" (currently only the Twilight Hack ) would be to press new discs or have the system patch the game upon loading it. The likelyhood of the former depends on whether or not they intend to keep fixing bugs anyway -- this hack is probably not enough reason for them to restart production of the discs. (That having been said, there are already two different NTSC/US versions of that game, so a third could be released.)
Patching the game while loading is unlikely for a number of boring reasons. It's a lot of work with very little benefit -- until homebrew activities threaten Nintendo's revenue, don't expect them to expend serious effort to stop it.