"The monolithic applications, installed in the 90s, didn't talk with one another, there was no flexibility for the business to adapt to changing business processes."
I don't know with what verticals and horisontals you've been involved, but that statements belongs more to 70s and early 80s then to 90s.
What is constantly changing is the enabling integration platform and technology but to characterise applications that were built in 90s as monolithic that did not talk to each other, is simply an overstatement.
Service Oriented Architecture certainly represent a leap in the way applications are being designed, but that is still conditionally said, as most of those services will still be implemented as layer(s) on top of the existing legacy systems.
It is the integration of services with the existing systems that remains the biggest area of concern and effort. In realisation of that fact many application software vendors are switching their focus into exactly that area where only few names are major players today. SAP for instance is making a big move into the area of EAI.
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