I've recently installed a Trac instance on Windows and Apache 2. Initially I had it running under mod_python, with very good results. Just today I've switched to mod_wsgi. An elegant and very small module easily replaced its big brother with no loss in functionality or scalability. Installation was trivial: just copy the module file into modules/. Configuration was straightforward, following a single short Wiki page. After installation, I conducted some non-scientific tests, and both response time and memory consumption were roughly equivalent for mod_python and mod_wsgi. For the latter, it's a significant achievement. Approximately seven years that separate the two projects' start dates didn't go in vain of course: I believe mod_wsgi contains condensed experience that was accumulated while building the solid and still very much relevant mod_python (that I personally have been using for years). But with WSGI becoming more and more important, and with such great experience with mod_wsgi version 1.0, I'm convinced that it will take over and become the primary means of running Web applications written in Python. The biggest hurdle in mod_wsgi's path is, I think, adoption by ISPs. Mod_python never really caught on, so I'm very hopeful that mod_wsgi is much more welcome among Web host companies.
We're using mod_wsgi for microPledge.com, and it's simple to install and fast. The source is clear, and Graham D (the author) is very helpful on the mod_[wsgi|python] lists. See more at my blog entry about it: http://blog.micropledge.com/2007/09/the-up-and-coming-mod_wsgi/
I tried lots of ways to serve MoinMoin (a Wiki Engine written in Python), like CGI, FastCGI, mod_python, Twisted, ...
mod_wsgi was by far the best experience I had - a great piece of software written by a developer who cares about Python web hosting.
It is simple to set up, fast, powerful, secure, it cares for stuff you need.