No sweat! It's my fault for not being more specific in the summary, anyway.
That's a fair point, but it's unrelated--the point is that the XBLIG games you already own will arbitrarily stop working when Microsoft eventually stops supporting the 360. Having to buy the game again on the new system (assuming you get the new system) doesn't help with that.
One point to consider: as far as I know Xbox Live Arcade Games don't require an Xbox Live connection (unless you're playing online, of course), so I don't think they should be affected by this.
Exactly my point (and I should've emphasized it more)! Games for The One have similar (though not exactly the same) DRM restrictions; it's not outside the realm of possibilities that when the Xbox Two comes out, your entire One collection will be unplayable, too.
It's true that a lot of them have PC ports, but still--the games people already own won't work, for no reason. At best they'll have the option to purchase them a second time (unless the DRM restriction gets removed, anyway).