Hi, my updates are done in something like about 2 - 3 mins, and the web browser was done in about 6 mins, including connecting to the wii shop. Maybe you are hitting a time when everyone is downloading.
Or it is cause you are wireless sharing a internet connection thru the laptop to the Wii, my Wii is connected directly to the router via wireless and not using a computer/laptop with ICS enabled. Connect the Wii straight to the router, not use a wifi point on the laptop.
Hope this helps.