Well, I went for it. I decided to plunge into upgrade mode and download the new version of Movable Type.
So far I’m quite impressed. I’m not sure that there are any huge improvements, but they’ve changed the back-end interface completely and it’s rather nice. The upgrade went well enough, although the database conversion took a while. I don’t seem to have broken anything important, which is a definite positive in my book!
I’ve not tried much of the new functionality just yet either, but so far it looks nice and stable and it didn’t break my template.
I’m still not tempted to switch to WordPress. I’m not a huge fan of the backend of that, as good a product as it is. Plus I’ve read that the templating is even harder than Movable Type.