Virtualization is in many ways pure goodness, just as proponents say. But even so, I think it’s being overhyped. As software, hardware, and processor vendors all get larger, economies of scale are allowing very tight development coupling so as to optimize performance, power usage, etc. For example, I’m running into Intel engineers at almost every large company I follow. If you buy software — and who builds their own if they don’t have to? — you’re now likely to get something that’s been carefully optimized for very specific operating environments. And then there are appliances, which are still trending up, not down. (See also what Stuart Frost of DATallegro has to say on that point.) Or check out this ostensibly pro-virtualization article that really is in agreement with me.
None of this means that you need to run tons of stovepiped OLTP database applications, each on their respective legacy platforms. Physically consolidating those is a great idea (although in lieu of logical consolidation, loose coupling via SOA, et al. may be much more effective — which is kind of the whole point of DBMS2). But it gives pause as to whether a wholly virtualized environment will be “the” computing platform of the future — or at least as to how soon that future will arrive.