Thought I'd pop in a note about my Relationships Blog that I had running under Drupal for 2 years and converted it over to WordPress just before Christmas.
It took me a few weeks to do, once I got some assistance in converting the Forum part of Drupal over to bbPress, by the guys at gComvertor. In hindsight, I should have just got them to do the entire conversion and saved the labour.
Learning curve was minimal - still having a few permalink hiccups which I think is some minor conflicts between a few permalink plugins I've used to retain the friendly URL structure of my previous site and search engines.
I must say most things are a whole lot easier so the next step is working out the shopping cart side of things and the theming. It's a great pity that bbPress is a plugin that fails to respect the site theming that I have in place as well as theme shortcodes and using a different paradigm as far as content types go.
All in all, I'm a much happier camper with WordPress than Drupal - never thought I'd be saying that though.