I too at first thought this name was out there, but I assume I will get used to it just as I have all the other things that have occurred like this. Its just the initial shock of something totally unexpected with a name that is completely odd.
However, I think Nintendo knows exactly what they are doing. They knew this would be huge news and people would react all over the place. So they release the name 2 weeks before E3, have everyone talking about it (good or bad at least its on their brain) and by E3 the initial shock is gone and everything will start to shift focus over to all the games they are going to be showing off.
And I don't get why everyone is associating Wii with that of taking a piss (beyond the haters of Nintendo that would have found a problem with any name they came up with). I don't know anyone who has ever said "I'm going to go take a wee". Now maybe little kids say weewee, but most of the world doesn't speak in such a way. I foresee in the coming weeks people will start to embrace the name more, I for one have started to accept it more if not for just all the hate its generated, I find it rather amusing how quickly this has become a recognized name.