I loooove Python. But if asked to "bet the farm" on a web app, I'd go with PHP because it's been successfully demonstrated again in again in every form of web app you can imagine. In a year, I'd recommend Python, but I still find Django and the other web frameworks a bit too immature and clunky to do things that PHP has been hacking with for years and years. As much as I hate to say it, for the Python community the web server has been an afterthought until the past two years. PHP was bred there.

I probably would say it's a closer call if we hadn't found a great MVC framework for PHP called Code Igniter that just makes PHP (of all things) much more pleasurable to hack in than it used to be.

All this being said, you're not risking much by going with Python/Django. But if the farm is on the line, I'd personally have to go with LAMPhp.