The troublesome birth of ATI's R520 "Fudo"
 

Yields are now very good and you should expect to see a massive quantity of X1800XT on shelves in about four weeks.

Yes, it's late; yes, was delayed and, yes, it's not available instantly but, still, we liked what we saw.

If you still haven’t bought a GTX card then it might be a good idea to wait for a R520-based X1800XT or check out the even more affordable X1800XL cards available now. The R520XL, named Radeon X1800XL and clocked at 500MHz core and 1000MHz memory is on a par with Nvidia's Geforce 7800GT.

http://www.theinquirer.net/?article=26932

Production YEILD factors are keys in chip manufacturing.

from what I've seen, there is no need to *wait* for the X1800XT as it costs more than 7800GTX and performs equal (if not a bit worse) in most games

not to mention the fact that no Crossfire master cards are present and motherboards either, so you have no idea of Crossfire performance.