I was wondering, how does a 'traditional' virtual machine setup with storage on iSCSI, with a fallback using DRBD, nodes with Xen installed the 'normal way', storing their images on the iSCSI target, etc. compare to Cloud solutions, like Ubuntu Enterprise Cloud?

Researching about clouds doesn't seem to give me much concrete information. I still have a bunch of uncertainties about is. For example, does Ubuntu enterprise cloud have integrated redundant/fall back storage and failover VM nodes? Can storage be expanded as simply as adding another storage node?

Let me ask it this way: is it unwise to implement a xen setup using the aforementioned tools now that Cloud stuff is gaining popularity? Will the 'old' way be deprecated soon?