I suppose an alternative to backpacks would be a hybrid solution with "smart" headsets (much like cardboard/daydream) and a tradeoff in cpu/bandwidth doing some work on the pc, and some on the headset - and streaming over wlan. But I don't know if that's really feasible wrt getting the latency low enough with a high quality display.
DisplayLink already has a working wireless adapter for the Vive. I've tried it, and it's really good. No need for gimmicky backback computers or non-replacable headset computers.
I thought the issue with current wireless technology was getting the latency down, in order to work with true ~90hz refresh (so when you tilt your head looking at the horizon, or move your head quickly the display updates in seemingly real-time, not showing you one or two frames of old data).
Is this still not an issue?
Today, a vr rig, hotas controller setup and elite:dangerous already is a killer combination for vr. Put the price is steep and the appeal is much more narrow than Mario Bros.
[ed: personally I think vr will be more of a paradigm shift, than a game gimmick though. I think creative tools like tilt brush will combine with multi-user world's a la second life or croquet/open cobalt. And I think it'll grow a bit "top down" first: with early adopters and creators / developers.
But one thing that has to go are the wires - probably first by higher performance/watt and a move to "backpack pcs" to run the software.
Before that, Sony has the right idea: lower ambitions and let players sit in a sofa. Works fine for driving/simulators etc. ]