Nope, been suggested before and it's not gonna happen anytime soon until the networks are ready to sustain it. The problem with unlimited data and instituting a fair usage policy is that people constantly abuse the "unlimited" feature and put a strain on the network. Wind's so cheap because their network isn't as big, reliable, or fast, which is important to a lot of people. It's a toss up.
If you live in their coverage area and don't mind some dropped calls or slower network speeds then by all means go for Wind. It's working for over 700,000 people at this point.