TheDailyWTF.com has an interesting article titled Anatomii of a Hack which looks at the process by which the homebrew scene has been getting into the guts of Nintendo's super-popular console:

Wii hacking for the consumer isn't hard to do, as instructions are readily available online, and the only necessary supplies are an SD card and Twilight Princess. Homebrew applications include media players (including DVD playback, not natively supported by the Wii), emulators, games (originals as well as Quake and Doom), file system browsers, and a version of Linux (surprised?). There's even a utility to change the Wii's region, which is now being used for buying (yes, buying) WiiWare games that haven't been made available to all regions.

For the most part it seems that the homebrew scene caters to the geeks who want to see what they can do with the system. Sure, there are those that use these powers for evil, but the intentions of the majority of the community are pure. The Wii isn't just a games console, it's an interesting challenge that has brought people together for little more than the joy of hacking, experimentation, and creation.

Bit more on the technical side of things but it's a good read and gives some insight into the ongoing battle between the modding community and the corporate overlords that want to prevent it.

Some of the articles and videos on the technical aspects of modding/hacking are just pure awesome and captivating. My favourite is the "Deconstructing The Xbox Security System" video from a Google talk. I was hooked for the entire hour of the video, even though I know very little about nor like consoles. I'd recommend it to anyone who is even remotely interested in programming or computer architecture, regardless of your knowledge level. It's fkn genius work:

With these Wii hacks can you still play legit games, and even other region retail games (provided you region hack it)?

Yeah you can still play legit games. What the hack does is just install a custom channel on your wii. From that channel you run homebrew and programs. It's pretty cool.

Stay tuned, the fellas at www.HackMii.com (the ones who created the Twilight Princess Hack and the Homebrew Channel, making Wii homebrew possible) will soon be releasing their next big thing, called BootMii. If you want the details, go have a read on their site, but basically what they're creating is a means to have total control over the seystem, that includes patching or even completely bypassing the Wii System Menu.

They've already got a demo version of it available that you can use, it's just that you can't install it permanently at the moment. I've used it to boot games from other regions, and it works awesomely.

Does "boot games from other regions" include burn games from other regions?

Not without a modchip. I'm sure that's not far off though.

Some backup games can be done without a mod chip, although the Wii only reads them at 3x speed.