I hope you enjoy your bricked Wii after the next update from Nintendo. -_-;
No way in hell this will lead to nintendo bricking wiis.
No hardware modding is required, nintendo can't brick Wiis because of the homebrew channel, it's just as likely as the Mii channel bricking wiis.
Anywho, the wii scene is progressing very nicely, external HDD support is making strides which will be great for media players and perhaps an iso loader in the future.
Impressive that anyone can easily create their own channel and have it look just like the official ones already, hopefully it won't be too long before homebrew games specifically for Wii and maybe some tech demos
edit-
I'm waiting till they can make full custom firmware for the Wii.
It's hard to say if they ever will need to.
Custom channels are already working, if they can put an iso loader together a custom firmware will probably never be needed