http://www.gamespot.com/articles/xbox-one-backwards-compatibility-could-one-day-wor/1100-6429894/
Probably not a big deal to most, and might not be something that would actually happen, but man it'd be sick if it did.
it'd be cool I guess but how many OG Xbox games would you really play regularly? And most can be played on 360 currently, which you can buy for almost nothing if you sold yours.