I recall reading something about the version of a certain piece of hardware Dell choose to include in the phone. The particular chip (Qualcomm I believe) doesn't allow for broadcasting of N band wireless networks and doesn't enable recognition of hidden WiFi networks, thus no tethering and only public wireless networks for now. Again this is just what I've seen her and there so don't quote me on it haha.
I've heard talk about a firmware work-around despite hardware limitations so there is some hope, but I'm not going to get my hopes up for now.
Sent from my Venue Pro using XDA Windows Phone 7 App