No good, Anarchy. Even soft-mods leave "traces", and the use of Any Title Deleter to remove all the hidden crap doesn't change the fact that ATD itself still leaves its mark. Nintendo will scan for that stuff and charge you extra fees for removing it (very nearly the value of a new console, and that was before the price-cuts).
That said, I believe the risk to be worth it. I'm a fan of homebrew-emulation; as awesome as the VC is there are still plenty of great titles that it still lacks, and can be homebrew-emulated to perfection (Godzilla Monster of Monsters, Act Raiser 2, Star Fox, Star Fox 2, Yoshi's Island, MMX2, MMX3, and all manners of GameBoy stuff, just to name a few). Even some classic arcade games like The Simpsons (unfortunately, MM2 Power Fighters doesn't work, and N64 emulation is still sketchy). Plus, the insane sweetness that is Riivolution, allowing file-replacement hacks to work in conjunction with your original game discs. You can have LOTS of fun with Brawl and NSMB that way.
If your Wii dies, you're not getting any save data/shop purchases back without a hefty fine. That's the risk you take, period. BootMii helps offset it in terms of your system's software getting corrupted (if you have an old enough Wii to install as boot2, that is), but in the event of a hardware failure you'll be SOL.