There are a total of 9 ports on the Wii all together:
4 GCN controller ports
1 Power cable input
1 Composite cables input
2 USB ports
1 Sensor bar input
There shouldn't be any confusion to putting in any of the cables to to ports on the Wii if that is what your thinking about. The power cable input, composite cable input & sensor bar input are all different sizes so there shouldn't be any problems there.
4 GCN ports to plug in GCN controllers for playing GCN games or any game that allows the use of the GCN controller like VC titles and some Wii games for example.
The 2 USB ports on the back can be used for multiple things. You can plug in a keyboard, Wii Speak, 3rd party cooling fan etc into the back of the Wii.
There would be 10 inputs however if you include the use of the sd card as an input.
Unlike Sony & Microsoft, Nintendo does not redesign the hardware or add additional features to different versions or manufacture different versions. Only once has Nintendo done a redesign of the hardware for a home console and that was of the Super Nintendo Entertainment System. The latest Wii is the same Wii that was released back in 2006. The only difference i can note is an internal part was switched around spring-summer 2007 (or 2008: Can not find exact reference) for a newer/different version. The Current Wii's bought now start off exactly like those that were manufactured and bought in 2006. Nintendo does not update the frimwire with the newer Wii's surprisingly. You must update it yourself.
I hope this answers your question.
~Barolb