python web app in prod
You don't give enough information to answer this question. What is your web service doing (apart from serving JSON)? Where does the data come from? How many different types of output are there? How dynamic is it? What sort of processing is required? Does it need authentication? Does it need a database connection? Will it be REST? Does it need to handle POSTs as well as just GETs? And so on, and on.
Your proposed solution might be good (although like Lennart I don't understand what AJP is doing in there), if you just very simple requirements to serve a few different types of content on a read-only basis. Again, though, if you have anything more complex you may want to look into Django + Piston, running on Apache + mod_wsgi.
I am considering to use python serving json based web services, my priorities are, in order:

maintainability
easy of coding
high availability
performance

Apache->AJP->Flup->Python seems ok to me, would you recommend another setup or is this ok ?