Ronan Bradley has an interesting article about Oracle's "Three Styles of SOA".
He lists the three styles as:
• SOA based integration
• Modern, composite application development
• Modernising mainframe and legacy applications
... and claims that no vendor has a tool that can do all three.
I must admit that I don't know as much as I should about mainframe modernisation but for the first two, I suggest he takes a look at WebSphere Process Server.
I would argue that it does both - and does both very well.
The reason Process Server can do this is, in part, the Service Component Architecture. SCA provides a framework for building new composite applications - and does so in a way that makes integration solutions very easy to build (i.e. the metaphors and abstractions that are used in SCA - coarse-grained interfaces, "business objects", etc - are precisely the ones that make typical integration problems easy to solve). In other words, WPS's support of "style 1" is almost a direct consequence of its ability to support "style 2".