Well. Finally I got everything that I needed done to finalize the upgrade to WordPress 1.5 (Beta 1). The new theme system is wonderful, as is the possibility to create pages that are out of the blog sequence. The archives and colophon are examples of plain pages.
What took me so long was that I wanted to create a theme that is similar to what the design of the site looked before the upgrade. At the same time I took the time to clean up quite a bit of the code and make the site more consistent. I should have most aspects covered, but some small changes may still come.
I don’t have any other plugins (except Geo) installed so far. I’ll be looking into making some of my own plugins as well. More on that later.
I recommend upgrading even though it’s still a beta version. At least I haven’t had any issues with it so far.