Intel mainstream offering ends at P4 2.6 Ghz. The 2.8 one is clearly out of market.
A64 has enough cool features besides Sysmark score to make it attractive. It will definitely win 3-4 essential benchmarks over P4 3.2, attracting those who are interested. It will be a big luck if Doom will be among them. It will be pretty cool and silent, it leaves more space on the matherboard letting someone to design some cool mini/micro-atx boards with many features. It will be binary compatible with Opteron, making it good client and development machine in the 64-bit directed enterprise. Finally, it has an extremely high geeky factor, making it to just look more sexy than P4.
Doesn't look like a blockbuster, but many people waited and they will not be disappointed. Not everyone upgrade right to P4 3.2, most people upgrade to P4 2.6. Then A64 will be clearly a better choice than P4 2.6.