What is the feasibility of encrypting VOIP traffic to bypass the "scanning" for VOIP packets?
It's theoretically very feasible, and there's nothing the networks can do about it (unless they happen to have quantum computers sitting in their server rooms . . .)
The standard Skype protocol is already encrypted, although I've heard conflicting reports whether Skype traffic is actually detectable by examining packets. One of the problems is that the Skype protocol has not been opened to external review.
However, there's no reason why VOIP calls can't be routed over encrypted anonymizing networks, e.g. Tor (tor.eff.org) or I2P (www.i2p.net), which, assuming there are no bugs, *really can* provide undetectable routing. Unfortunately, many of these "mix" networks depend on volunteer networks of PC's and tend to be on the slow side. If you believe strongly enough in the cause, donate to the Electronic Frontier Foundation (www.eff.org), who have been relatively active
The danger of not resisting is that we become a milkable proletariat for the telecomms companies . . . (somewhat hysterical, but true, I think)