I disagree when one says that because no rc5 core is optimized for a cpu, the rc5 benchmark for that cpu is meaningless.
It does mean that the itanium is unable to run some software that people currently use. So before anyone goes out and buys one, he has to test every programm he uses to make sure the new expensive chip isn't going to perform like a 486.
Hell, if I work with photoshop and make heavy use of a particular filter that is heavy on a particular set of instructions, and I find out the itanium sucks at it, will I wait 1 year for that filter to be optimized for my cpu ? I sure will get another platform to work on. That goes for all other software.
When the athlon was out, no core was available for it but it rocked rc5 already. I dont mean HW vendors must not innovate and stick to old standards, just that abrupt innovation can not win the market at once ; software has to follow. If you run too fast, you end up hitting a wall.