Rails's community advantage over Django looks like something that is not likely to go away in any foreseeable future. Although Sinatra is getting popular, Pythonistas are split between Django (or the AppEngine variant), (Jinja), Tornado, Flask, Jekyll, Pylons, and so on.
With Ruby, Rails oftentimes seems like the obvious framework, whereas the same can't be said for Python and Django.
Getting into Django has been a bit of a pain in the ass for me - at least for being unable to work on it organically with some fellow students or co-workers - but is there any reason to believe that getting a big Python framework community similar to Rails's is a plausible prospect?
I don't know where you are getting the idea that Django's community is more than marginally smaller than Rails'. Google Trends, StackOverflow questions, number of GitHub projects, average followers/forks for popular Django/Rails extensions, number/popularity of significant sites built with each, and the number of stories I see pop-up on sites like HN for each framework are all relatively equivalent.
Django for AppEngine is barely a variant, it's just a different handler for the ORM to interact with the non-relational backend. Jinja's a template engine that you can plug-in on top of Django if you want (like if you wanted to use HAML instead of ERB). Plenty of Django devs choose Tornado for their COMET needs (I know of almost no one that uses it as their entire web stack). Flask and Bottle are nice micro-frameworks, but aren't well-suited at all for large sites unless you feel like doing a lot of extra work yourself. Jekyll isn't a Python project, it's Ruby's static site generator (but does have a Python port called Hyde). Pylons (now Pyramid) is the only significant contender to Django. Think of it as Sinatra's market-share compared to Rails.
So when you actually compare the two, Python has no more "framework fragmentation" than Ruby. To someone outside of the community just listing off frameworks that they found on Google, sure it might seem that way.
I would say his comment stems from the apparent lack of knowledge regarding the different frameworks that are available Python and the lumping in of a Ruby project with Python projects.
From an outside perspective it looks like you are skimming the service and do not yet have a firm grasp as to the two communities and what they have provided. This is okay, it is something you can alleviate by simply learning more about the two communities, and hopefully in the future you will be able to provide your opinion on the state of frameworks based on correct information/facts.
I see it as unlikely there'll be real consolidation, ironically for a language with a "one obvious way to do it" philosophy there many different opinions about how a framework would work. That said there is progress on consolidating some of the infrastructure, e.g. discussions on a creating a unified request objects for frameworks, a GSOC by Armin Ronacher (author of Jinja and Flask) under the Django banner to create a unified template compiler framework for both to share, and a work-in-progress PEP by Laurens Van Houtven about unifying some APIs that asynchronous frameworks have and bringing some useful base classes into the stdlib.
With Ruby, Rails oftentimes seems like the obvious framework, whereas the same can't be said for Python and Django.
Getting into Django has been a bit of a pain in the ass for me - at least for being unable to work on it organically with some fellow students or co-workers - but is there any reason to believe that getting a big Python framework community similar to Rails's is a plausible prospect?