Guys, I'm gonna throw in my 0.02 c.
The only problem with linux is hardware support. You have to make sure the particular hardware is supported or resort to using the less efficient NDISWrapper route. I found this out the hard way last night. (MRD, check my cry for help in the Blue Room).
So, no drivers exist for the Netgear WG111 wireless USB device. What could I do? Nothing really. I was loathe to use NDISWrapper, as the convoluted procedure threw me off (I'm a newb). The next best alternative was to check NIC compatbility and pick the NIC that had drivers. So I headed out to CompUSSR and purchased an NIC for $15.
So, as long as this situation exists, I don't think we will see widespread adaptation of Linux.