Besides discussion on the thread itself I had a lot of private comments in my mail from Sun/MySQL employees which tended to agree with me on this being the a large stretch.
I would hope Sun/MySQL would tone it down and actually spend time on making things to scale inside MySQL rather than asking you to run tens of MySQL instances to get reasonable performance, but sure enough writing code is harder than writing marketing materials so this work now made it to the Sun blueprint making it recommended reference architecture.
It is also interesting to go back to my old post about T2000 performance with Sun comments about Sun not pushing this as scalable MySQL platform. Well this is T5440 now not T2000 but the outstanding gap in single thread CPU performance remains, which makes a lot of operations tasks very complicated.
Oh wait. I forgot there is solution – instead of 1TB database we should run 1000 instances with 1GB each which will allow us not to care about single thread performance for replication needs, ALTER TABLE or any long running queries.
Do not take it as me saying T5440 is never good for MySQL. It may work quite well for some cases, for example when a lot of small MySQL instances need to be run. It is just this blueprint offers very one side view speaking about benefits but no drawbacks.