SOA = Lipstick on Pig
Some of the big motivating factors for moving away from the old lamps is an inherent desire of developers to get closer to a new technologies capabilities thoughout a systems aspects (yes, I am referring to the interest in AOP even if I do not wish to actually use it) and thats a big deal. Adding layers of indirection and wrappers around legacy technology to make it work with the rest of the business is the issue at hand and the harder it is to do this, the bigger the financial pressure to move away from what would otherwise be a perfectly acceptable tool for the job.
Of course this was the promise of SOA, Service Oriented Architectures; wrapping legacy systems and allowing a fluid interop with new business platforms and user interface technologies. Of course we are just shuffling complexities from one place to another - managing a core technology migration instead becomes managing a zillion interfaces and service clients all of whom do different things. This is not to say that this has not been successful in many cases but it certainly is not the painless nirvana marketers would have us believe.
The really big deal about SOA and now virtualization is that it is thinking about the business not just the technology. There are some vast investments in technology and platforms and wrapping them up through services, virtualization or both is a good way of managing the shifting targets of performance, scalability and COST whilst allowing newer platforms to be a little more agile in their approach (Service orientation can be a good thing).
So what does this mean for the Old Lamps? Well, for sure it means that there is some longevity in the original technology and the irony of this is that there must be skilled people out there to maintain it. What do they do when they stop maintaining those old systems running in a virtualized VAX-11?
Write grid batch processors I'm sure...