What this mod essentially does. is allow you to store DOL files on the modchip itself. DOL files are Gamecube executable files, so it allows you to send small apps across. Not bioses.
Do you guys remember the old PSO Exploit, where you could send small apps across to your GameCube using a bug in the network connection? From here, you could send across little 'loaders' that could stream the games from your PC...
This mod really doesn't provide anything that the previous method could not... it just saves you from having to boot up PSO.
This is a rather cool little mod if you would like your apps to automatically boot up when you turn in your GameCube... GC-Linux anyone? And you can send across the afrorementioned 'loaders' you boot yer Iso's... but this isn't going to help you play games from disc, nor is it going to help you use a hacked bios replacement. Sorry guys.
The main reason a 'proper' modchip for the GameCube does not exist yet is because it uses proprietory discs, not mini-DVD's as people seem to believe.
I gather it's theorietically possible to boot a DVDR on the Gamecube... but it would require hacking of the drive controller, as opposed to merely hacking the bios.