There are 2 reasons I use WEP.
1. The Wii is a pig to set up with WPA
2. If someone really wants to break in, I doubt WPA would stop them.
It's really just something there to deter people when there are easier
targets around really.
If anyone out there thinks there is no real difference between WEP and WPA, I would very strongly advice them to list the following Security Now podcast, which might well prove to be a bit of an eye opener:
I didn't say there was no difference. It's just that if someone really
wants to get in, WPA wouldn't really stop them (all the need is an
insecure box on the network really and since I don't maintain my
housemates machines, I can't guarentee they're secure.) Once they're
inside though, I doubt they'd get much more than the interwebs or my
housemates machines. If I had something worth securing I'd secure it
more thoroughly. Since I don't it's a bit of a waste of time really.