Open lending == piracy. Closed lending? Well, I've yet to see a secure and easy way to accomplish this, so I'll reserve judgment. But given how Amazon has treated the eBook distribution model, I would expect all digital goods to go down a similar route (no transfer of rights, lending is more of a trial period than anything, and no two copies running at once). All existing models are confusing for both end customers and rights stakeholders, and there is no way to do it in an open manner.
Let's say MS figures out how to let us share games, but it requires a central licensing authority (MS) to negotiate the transactions. Would you not agree the same geeks arguing the lack of sharing now will be the same ones to pick at that system too? It's a moving target, and doesn't do a bit of good for the stakeholders. I'd expect to not see this sort of system to play out.