really, I don't see a reason to disheartened, unless you still had partial ownership or a stake in the Wii. If you did and he sold it without telling you then he would e kinda of a dick. As it stands, he made a choice many of us here would not make, but nothing unethical or amoral.
Think of it this way ... when you visit you can play PS3 games. My brother has a Ps3 and when we were roommates I played the system quite a bit. Now he is on the other side of town and one of my roomates has a 360. Nothing wrong with them having "enemy" systems. I can play them as well.
My brothers ps3 has been acting up lately and I have been thinking of making him a offer, as he just bought a 360 and enjoys it.
"But as always, technology refused to be dignity's bitch."--Vance DeGeneres
