There will no doubt be a continuing series of Athlons come out, even after the Opteron debuts, and they will more than likely fit into existing Socket A main boards. We don't know this for certain, of course, but we can make a reasonably confident prediction based on past history that the AMD parts will maintain their currency for longer.
There are two factors to consider here:
(i) The relative age of the platforms. Here, the P4 is the winner: it's a good twelve months younger than the socketed Athlons, and it's reasonable to assume that the P4 will go on longer than the K7.
(ii) The track record of the manufacturers. AMD's is pretty good, Intel's is appalling. Consider the number of platform changes the two firms have inflicted on us since Socket 7:
AMD
Socket 7 (K5, K6 Classic)
Super 7 (K6-2, K6-III)
Slot A (Athlon Classic)
Socket A (Thunderbird, Duron)
133MHz FSB Socket A ("C" model Thunderbird, Athlon XP)
Total: 5
Intel
Socket 7 (Pentium, Pentium MMX)
Slot 1 (Pentium II, Celeron)
100MHz Slot 1 (P-II 350 and up)
Socket 370 (Celeron A)
133MHz Socket 370 (Pentium III)
133MHz Socket 370 again (Pentium III final versions)
Socket 423 (Pentium 4)
Socket 478 (Pentium 4)
533MHz Socket 478 (Pentium 4)
Total: 9
Intel, in other words, have almost twice as bad a record as AMD have. You were very lucky with your BX, SYROB. I'd as soon trust George W Bush to cancel defence spending and increase welfare as trust Intel to preserve my motherboard investment. Yes, they have the newer platform, but it's odds-on that Socket A will outlast it. It is ageing, but it has already outlasted no less than four Intel platforms. And in any case, you spend roughly half to two-thirds as much to buy an Athlon as you do to buy a P4 - so even if you guess wrong and the Intel platform lasts longer, you can afford to buy another board and still be no worse off.
And you can be absolutely certain that two long-lasting AMD platforms will outlast one short-lived Intel one.
