We just finished a small project with the primary aim of giving Microsoft StreamInsight a try.
The technology looks fine, but I have a concern about its industry traction. When we ran into issues there were only a handful of materials on the web and generally I miss a vibrant community around it.
Should we expand our use of StreamInsight or it will go down the drain in a few years like Silverlight did?
I was at a SQL user group meeting about three months ago. I asked that exact question of the speaker (Microsoft Blue Badge). He didn't make a definitive statement but from what he did say it was clear he thought StreamInsight had a big future.