JP of ModPubsubPeople provides a nod of recognition to .NET - I guess I am now obligated to contribute something from my mod_pubsub-fueled smart client tinkerings. ;)
Agent provocateur Philip Greenspun takes a slap at Java for being "the SUV of programming languages" (and being a resident of Cambridge, he doesn't mean that in a nice way).
I actually rather like Java in the abstract -- it's like a kitchen with all the fancy appliances! -- but I find that in the mod-pubsub context it always seems just a bit too... heavy. Who wants to fiddle with a bunch of CLASSPATHs and fire up Eclipse just to write a little connector? Increasingly we find ourselves reaching for Python (or .NET, for those of us inclined that way) instead.
In general, I think Java maybe encourages "big architecture think" -- which I've never been convinced is the right paradigm for the Internet. I love rolling out heterogenous Open Source packages without worrying about what they're written in or if they go together. Technologies like mod-pubsub will supply the lightweight integration that makes them go together. So the job of the architect might not be to make sure that a platform is all-one-technology from front to back -- but to keep track of all the various parts and make sure they hang together properly. [Mod-pubsub blog]