It's a pretty smart move from ati as this allows them to monopolise the higher end agp market with nvidia having nothing in that area to even touch the x1800s. Unless they decide to bring out they're own 7800 equivilants (even though they stated they wouldnt) which seems likely as they have been counter-acting every move ati make recently.
I cant see agp going past the x1800 series; sli is going to be very important in the future, especially with the unreal 3 engine around the corner.