I found this very interesting atricle on how Virtualization and Cisco Nexus combine to eliminate blade servers. Now, personally I've never been the biggest fan of Blade servers. yes, maybe for Citrix environments, they seem to be perfect, but I've never seen the need and flexibility of them in virtualized environments.
The article below looks at why blade servers have never really made sense in Virtual Infrastructure Architectures, and I have to say I agree with all of it!