MS wants to sell precisely one license but support both never-connected machines and cloud lending, but this was too hard for them to figure out and they're dropping the cloud part.
The cloud lending facility required expiring leases (think DHCP) to guard against the possibility of a purchaser intentionally stranding their license at a friend's house (or on a dead xbox, or one that loses internet connectivity), where that friend would play happily for weeks without connecting to the network.
If you believe in the effectiveness of copy-proof-disc DRM, then a single token permitting ongoing play can certainly just reside on the disc.
How about this:
1. disc alone doesn't suffice to play a game on an unconnected xbox (so never-connected users are out of luck)
2. net connected xbox alone can acquire the right-to-play token as long as the previous holder of the token is online. (physical disc from store would need insertion only on first use to create the initial on-net token).
3. an unconnected xbox that was the last one to use the net token may continue to play indefinitely without net access, provided the disc can be validated. this does allow simultaneous play of at most one online and one disc, but only as long as the xbox stays intentionally unconnected (this limits the number of extra licenses to at most 1, unlike a more lenient cloud-lending policy that allows continued play without check-ins).
I believe the renew-lease-every-24hr model already allowed simultaneous play in case of the last token holder being offline (if the game didn't require a connection to play, that is).
If absolutely prohibiting simultaneous play from a single purchase is a must (and I don't see why it should be; an average concurrency of strictly less than 2 sounds fine), then you just need to require explicit lease releases (and the disc becomes irrelevant again), which has an obvious customer service overhead when people can't release for whatever reason.
Alternatively they could implement a physical 'disc destroyer' that can move a game (one-way) to the cloud phone-home mode. Or just require an xbox to phone home before permitting a new disc (giving up on never-connected xboxes), in which case no physical destruction is necessary.
Currently I own a Korean Xbox 360, as I bought it in Seoul while living there years ago. Since moving back to the US I have not bothered buying any new games mainly b/c I don't want to deal with having to worry about region locking.
It will be interesting to see how ownership and digital files interact in the future. Do I even own any of my digital files?
It looks like Microsoft doesn't anymore, either. The "no region locking" announcement today was an unexpected surprise.