Are they ashamed of the software or something? I honestly can't comprehend why so many projects are so shy about telling us what they actually are!
Every page should have "an open source Python library for rapid development of applications that make use of innovative user interfaces, such as multi-touch apps." on it. There is no reason not to. Put it in small text under all main titles or something.
I think the thinking is that, "Hey, this is an announcement for us, and our friends, you know, the folks who know all about this software already!". In general, do you care about an update to some software you don't use?
But, surprise surprise, someone in the in-crowd throws this up on HN and it blows up, and suddenly they have a ton of new, confused, visitors.
I think your idea of putting a summary on each page (including, or perhaps especially, the blog!) is a great idea. Why don't you tell them?