I don't expect multiples for some time. Right now the lanes limit the MoBos, and the power draw would be quite large for 4 cards.
While it may be possible (ALX has hinted at it for a while), it's not really going to go mainstream until they get the last kinks out of the 2 cards setups. Technically you could already do this with a tumwater board if it were to have 4 4X PCIe slots, but really there's not enough momentum yet.
Should you consider this in your purchase? IMO, NO!
It'll be at least 6-12 months before they start doing this let alone perfect it, and whatever solution they use it will likely use current CPUs, Memory, HDs, etc, so buy now, and then when it happens spend the $200 and buy that next gen MoBo, but for now don't worry about it. If you can afford 4x X800XLs even, then you can afford the MoBo upgrade then.
Intel getting dual core is interesting, but AMD's dual core will support 939 and 940 sockets so you're still safe with that route, going with an Intel solution now would leave the only questions, so if you MUST go Intel maybe you should wait.
Next big step for AMD requiring a rethink IMO, will be DDR2 and that's not until 2006, and really not as big a deal.
- You need a licence to buy a gun, but they'll sell anyone a stamp <i>(or internet account)</i> ! - <font color=green>RED </font color=green> <font color=red> GREEN</font color=red> GA to SK