I gave my presentation (slides here) this morning to a smaller than I'd expected, but still very interactive crowd. The discussion was about what Web Services Intermediaries are and why they're important to business hoping to scale SOA-based applications. I based most of what I said on things I've written for InfoWorld over the last year. I touched in one slide on a cross-section of vendors in this space and what their strengths are. Its clear that you can't pick a WSI vendor based on feature set. They differ much more clearly in the metaphor they use than the raw feature set. I've got an article coming out in InfoWorld about that.