While taking some time to peruse issue #8 of the Architecture Journal (an excellent resource, by all means), I ran into Tim Ewald's and Kim Wolk's article on "A Flexible Model for Data Integration". Pretty interesting, certainly in line with some of the service versioning stuff Tim has talked about.
I also found intriguing the concept of tying (connecting is possily a better word) the XML data model with the shared vs. system store model, particularly in the scenario discussed in the article - customer data - because it ties in with the common model in enterprises today of [partially] centralizing customer information in their CRM system, while allowing the recognizing the fact that some business areas (and thus the applications supporting them) will require extra data around it.
It's a pity this last topic was only briefly mentioned towards the end of the article; I'd certainly would've liked to see it presented in a little more detail (though the basic idea is fairly simple).