Netflix for games. It's a grand idea. There's already similar things, like EA Access for $30 a year that gives you older EA games. At $10 a month it isn't too expensive, but it's going to depend what the catalog looks like when it launches or over time. It's a rotational catalog, so one month you might have this set of 100 games and the next month 20 of those leave and are replaced with others and you can only play the ones in the catalog that month. I'll be interested to see what kind of games show up. How many 3rd parties, how many fairly recent AAA vs. indie, distribution of Xbox One vs. 360 games, and so on.
I think it is a novel idea that has huge potential. We'll just see how it goes. I suspect at launch it may appear underwhelming until they can get enough subscribers to convince publishers to put games in the catalog for a month or two (while in catalog subs get a discount, so it could drive purchases if you put it in for a month or two and then take it out).