I upgraded Typo to 2.5.0 several days ago, and I like it
even better. (I will eventually make this blog public, or else
there is little point.) 
I have a few ideas here. Some may be easy to implement, some may
be harder, some may be bad ideas. Comments welcome.
I'm willing to contribute to Typo myself, but I want to write a
complete Rails app on my own first. I've read tutorials and I've
hacked existing apps... but I want to do one from scratch. There's
nothing like "learning by doing."
1. I'd like to see per-category RSS feeds (perhaps with a link
next to each category, or at least changing the link at the
bottom while you're in that category).
2. I'd like a simple way to reorder the categories.
3. I think when you're in a category, there should be some way to
tell which one you're in -- a subtitle or something at least.
This should be trivial.
4. This may be more controversial. I'd like a way to generate tags
automatically (technorati, etc.). I know the category name is
tagged -- I think it is -- but nothing else is automatic.
As far as tags go, I know the links are "supposed" to be visible.
Yet I don't necessarily like littering a post with links,
especially since some (appropriate) tags may not naturally fit
into the text. The idea I've toyed with is to put a list of tags
at the end of the post -- perhaps in small print, preceded by a
horizontal rule, something like:
···
------------------------------------------
    Tags: foo, bar, baz
I'm not interesting in misleading the reader, of course, just in
comsolidating the tags, making cleaner text, and automating the
tag insertion.
Comments?
Hal