Clustering or Virtual Machine Replication?

In his blog, Virtually Speaking, Dan Kusnetzky (The Virtual Man) writes a great review of whether it is better to "deploy a clustered solution, such as SteelEye’s LifeKeeper or encapsulate applications and use a virtual machine replication technology, such as VMware’s Vmotion, XenSource’s Xenmotion or Virtual Iron’s Virtual Iron, to accomplish something" similar. 

Dan's posting covers critical goals of such a deployment including higher performance, increased scalability, increased availability, increased agility, and everything else.   It's a read that I highly recommend.