In all realism, I doubt you will see a Blu-Ray drive with X360 this gen. Not that Microsoft or Sony would prevent it, but Microsoft got its HD service going and no sense of adding another peripheral when they already have an HD add-on accessory this generation. Rather or not "Blu-Ray is great for making games", Microsoft is not going to release any game via Blu-Ray or HD DVD for 360. It always been stated by them that will not splinter their market. For the most part, they will release their games for the lowest common sku model, which is the X360 Arcade.
As for their next gen console, we will have to wait on that. For one, I see that what ever happens to HD DVD movie content, the format is still a viable storage media which Microsoft can easily use for it next gen proprietary game media. But I do see Microsoft adding the official winner of the HD media wars to its console playback feature set. So it might even be possible that you may see both HD DVD and Blu Ray in one console, especially if its cheap enough.
I really think that Sony and Microsoft will be toned down a bit for the next high end, all in one, super consoles due to the Nintendo console resurgence. I am personally happy with this, because consoles have got out hand with it features and causing it to be financially unaccessible (READ) to the middle class and below.
I'm just saying...
