Interesting, but it probably doesn't mean much for end users except maybe that they won't easily overclock to XT speeds.
Some thoughts on the X1800 line itself:
I really like the fact that they added proper AF into these cards and the performance is slightly better than reference speed 7800s (although most of the actual retail cards are overclocked to some degree), but these cards are very late and you still can't buy them. The XT in particular isn't going be out for at least another month and prices are going to be sky high for some time after that due to limited availability. A bit underwhelming overall IMO given the lengthy delay. Hopefully the R580 refresh parts, which are supposedly only a couple months off, will be more interesting and should fit in well with my planned upgrade anyway.
The X1800 cards seem to be the opposite of the 7800s in what they are good at. The 7800s excel in high resolutions and are decent with AA while these X1800s are great with AA and okay with high resolutions. It's a pity that neither line of cards does both really well.
