Video quality comparisons between HD-DVD and Blu-ray are usually bullshit because films released on both formats tend to have the same encoding (capped at 30GB), so the image quality is identical.
Blu-ray is the technically superior format and its potential will be realized, just as DVD's potential was realized after a few years.
There has been no firm announcement from Universal regarding their plans. Paramount issued a weak "we will continue to support" statement. MS has said nothing. The format war is over.