If you visit AMD's website and look at Barcelona's performance numbers you'll see a very rosy picture. Benchmarks there show performance numbers which most would desire. And yet, if you turn to the real-world benchmarks published today, the situation is much different.
The first benchmark listed on AMD's website is called VMmark Performance. It shows a 3.2 GHz Opteron 2224 SE compared to a non-existent Barcelona Opteron 2360 SE. They also use a "VMware ESX 3.5 experimental build 55263" release which is not available to the public. VMware's website shows VMware ESX Server 3i as their current product, which on build 52542.
The increase in performance for this benchmark is 124% over the much faster clocked 880 system. That's more than double the performance and it shows just how advanced Barcelona is over their previous architecture. And yet to obtain these high performance numbers, AMD is using a publicly unavailable processor on an build of VMware ESX, which is also not available. These numbers are not something we can duplicate in the real world, or even take advantage of yet. They show only what is possible with Barcelona, not what's available.