I think this is an interesting subject. At the last meeting I think only 3-5 people who attended worked with Django, that's not a lot. So it's only natural that fewer people are going to show interest. Although I do think there are quite a few people on the mailing list who did not attend the last meeting and have worked with Django.
It's not necessarily a bad thing that the size of the group is mixed from time to time. I think it would be best to organise events(of which multiple can occur during one meeting) based on three different categories:
I. Useful things for any Python developer
E.g.: coding style, useful standard library recipes, performance tips, testing tips,
introductions to some external libraries(e.g. some short and handy snippets with NLTK) , debugging, editors, specific interpreters(e.g. Ipython), ...
II. Useful things for either A. any web developer, B. any scientist or C. a person who works in the remaining fields that use Python (e.g. Telephony)
A. For Web developers:
E.g.: Css bootstraps, Javascript/JQuery/... tips, HTML5, how to best measure website performance,
decoupling from framework specific components using SQLalchemy, Jinja2, ... , ...
B. For scientists:
E.g.: Pystats, Matlibplot, Sympy, Mayavi, Numpy, ...
C. People of the remaining fields that use Python:
Could be anything.
III. Useful things only for people who use a specific framework in those of the groups in II
E.g. In group II, A: Django group and a Pylons group.
Personally I think we now need to find a balance of these categories of events during meetings. (Do we organise events only of one category per meeting or do we mix them in one meeting or do we predominantly try to organise a mix but only sometimes organise meetings of one category, ...?)
Although I think it will rather be determined by how many and which people offer to speak/organise and that it is not so much a matter of choice now.
Anyway, what I wanted to say is that you should not necessarily be disappointed when not everyone in the group shows interest for a specific event and that being aware of the rough % or # of people who are likely to be interested could provide consolation.