Webby is a great system and very close to what I needed; indeed I took many ideas from it. But webby does not help me with the blog specific parts that I wanted to have automated. The entire point of Jekyll is to remove every last bit of pain associated with creating, maintaining, and posting to my weblog.
Webby has a blog mode, though I've not used it, but I'm guessing it wasn't quite what you needed.
When I see people sort-of reinvent a wheel or two I wonder what the reason was.
Out of curiosity, did you consider forking Webby, or offering to add in the parts you wanted back to the Webby project? Is it easier to grab the ideas you like and start fresh on your own than to try to hack on someone else's existing code?
For myself, when I find myself writing something similar to an existing project, it tends to be because a) I wasn't quite aware of what the other project offered, b) (more often) the 80/80 rule kicks in: The existing code gives me 80% of what I want, but I'll be spending 80% of my development time trying to get the rest of what I need, and writing my own version looks to be more efficient in the long run. This is more so if I expect to be reusing that code for many projects, so I can readily see the motivation in creating your own blogging software if you plan on using the hell out of it, regardless of what existing tools do.
Jekyll is a re-implementation of existing projects except they don't have version control. I use rassmalog, which is small and easy to hack on, and supports plugins. There is also rog, and hobbix, both of which I looked at using but have not blogged with.
It features support for LaTex, markdown, textile filters, autobuild, publishing only changed pages etc. Very small and clean.
'gem install webby' is all needed to get you started.