In general JSON via HTTP or zeromq is so much cooler and more flexible than WSGI could ever be. I think if we accept that as a possible way to build applications out of components and start experimenting with it we could build some really cool stuff.
via lucumr.pocoo.org
This is something I was thinking yesterday. I tend to use WSGI stacking a lot on my development — on Pydap, for example, most of the additional functionality is implemented as WSGI middleware. Search is one example: I wrote a middleware that indexes all the datasets on a server, and injects an API (at /_search, IIRC) for queries using JSON. This would be much better running as a separate application, and there's no reason to run it in the WSGI stack.