They were supposed to be DejaVu, but they (2.4 P4) was released still at 100 mhz fsb. (Early IEEE news reports were that the 2.4 was supposed to be on 12" wafers as well, but that doesn't seem to have happened either.)
The "A" is only present on P4s at 2 Ghz or below to indicate the "Northwood" core is used. If I were looking to build/buy a P4 system that would be the only way that I would go. It's a pretty even in performance right now between the 2.4Ghz P4 and XP 2100+. AMD holds a small edge in price, but Intel's Northwoods are good overclockers.
IMO you really can't go too wrong either way, but be aware that both companies may soon release new designs that won't work on current boards. AMD is simply moving to a 0.13 micron process, which will require a lower core voltage. I don't know which boards can support this, but it will definately require a bios flash on older boards that can. Intel will be increasing the P4 FSB speed to 533 Mhz (133 Mhz QDR actually) on the next P4 release. Again, I don't know if current boards can accept these chips either. At the end of the year (if AMD actualy pulls it off) "hammer" will be released at tge 3400+ speed. It is certain that current boards WILL NOT be compatible with Hammer. (One version has 600+ pins, the other has around 900 pins. Current Socket A boards have 462 pins.) USB 2.0 is also starting to show up on boards, it's certainly an improvement over USB 1.1.
I'd personally wait a couple months.
