mine on 19 February 2015
There are TWO things I'm missing:
On the hardware side
- Gigabit Ethernet and the ability to use an iSCSI volume as storage.
This way all USB ports could be used by two GameCube Controller adapters.
At the moment I use a USB-Ethernet adapter and an USB Flash-Drive at the back ports.
At the software side
- easy backups. Even Nintendo network "cloud" based for the saves files only would be sufficient. Or tapping a button and those files go onto another medium...
Of course this wouldn't be necessary if an iSCSI volume could be used 
