For a while they were selling an add-on for the XBox 360 that would play HD dvds (the format that was the competitor for Blu-ray). As others have said, it won't play Blu-ray disks. And even though there are rumors that they will eventually add that functionality, it seems very unlikely. The games don't use that format, and older 360s wouldn't be able to play anything new that did use Blu-ray. Plus, that's one of the reasons that the PS3 is so expensive. I don't think Microsoft would add something that there isn't a big demand for that would massively raise the price of the 360. (Though apparently they could now, since Sony no longer has the exclusive on Blu-ray technology.)