With all of the security offered by VLANs/PVLANs, I could see why Cisco would be racing to devalue that multi-million dollar security investment in the Data Center. But it has been 5 years, so everything must be better now;

http://www.blackhat.com/presentations/bh-usa-02/bh-us-02-convery-switches.pdf

I think the next step up from 2.0 will be something non-numerical, such as LX, SX and so forth, or colours. Perhaps, instead of "Data Center 4.0", we might see "DCQuadMAXXXX", or "Data Center Delta".

Or "Data Center (Reprise)". Perhaps "Data Center (Movement IV: The Revealing Science of God, inc. Dance of the Puppets)".