It actually can't anymore Dave, I by chance was asked to mod a Wii today and the Wii servers have all been shut down from the 1st January - In effect, the Wii cannot connect to the Internet.
There is a long way round, but as I have not tried it, I won't tell you how to - it is called modmii, if you choose to do it anyway.
There were also certain games that had it on the disc, If I remember correctly.
The original question asked was not can you still softmod your wii, it was can you update to 4.3, which is what is in your video.
However, I will watch that in the morning to see if it is of any use to me, or the other member