But whether they'd store enough energy while autorotating to allow the helicopter fitted with such a lift source to successfully flare and land at a reasonably survivable speed might be another story.
And there again, you touch upon an issue in the V-22... though it does have wings. There are numerous hotheads over on the V-22 thread discussing this and other issues.
You can hover an airplane with enough power (Sean Tucker and other aerobatic pilots prove it often enough).
You can even hover a Harrier (though not for very long... you can see the fuel gauges moving).