SOA Development Methodologies

I actually work with Middleware products (Mostly BPMS's and ESB's) from IBM and Oracle (WebSphere ESB - IBM BPM - Oracle SOA Suite). Our SOA implementations are based entirely in these products (we don't implement SOA's written in Java, for example). In my experience with these products i have seen a lot of "vendor-dependency" and generalized difficulties when trying to align to a specific development methodology (like Scrum).

Based on that premise, i'm investigating a suitable set of practices / methodology, vendor-independent, that fits with these tools.

Why i'm saying "...that fits with these tools"? Because, in my experience these products are very rigid. Making a change in a service can be a headache: Propietary IDE's with Bugs (someone said "IBM Integration Designer"?), complex refactoring, "Coding" standards nonexistent, complex maintanability and other problems that these solutions can carry.

For these reasons and for the variability of complexity and size of different projects it's very hard to adapt, for example, a metodology like Scrum, but we know that Agile can help us a lot.

I've read this and this and i'm interested to know if Domain Driven Design can help us defining a common framework to work (these links don't refers to "Product Oriented SOA's").

Any guideline? DDD can help us? Another Methodoly / Paradigm?

Thanks