There are plenty of rumours revolving around the Xbox One backward compatibility feature at the moment. The main one revolves around EA Access, with a recent rumour suggesting that more B/C titles - including Mass Efffect - are heading to their service as part of the Vault.
Now though, Amazon US have added a bunch of new listings for digital codes that are listed as "works on Xbox One", all of which have a release date of June 14th, suggesting that a new wave of games will be added to the service on the opening day of this year's E3. On the retailer's site, EA titles in the form of Dragon Age II, Skate 2, Fight Night Round 4, Need for Speed: Hot Pursuit and Burnout Revenge are all listed, with Microsoft's own Fable Anniversary and Crackdown 2 are both listed as being en route on the 14th.
Whether or not this is the tip of the iceberg for a massive announcement of new titles at E3 remains to be seen, but it sure looks like something's coming. EA's "Play" conference will take place at 1pm PST on the 12th, with Microsoft's conference happening after the start of the usual trading day at 9:30am on the 13th, which makes the 14th June launch date for the new B/C titles make sense.