Interesting coincidence. After trying out quite a few of the apps recommended in the most interesting Note-taking software thread, I've been looking into writer's software. I came across a good round-up of the high-end shareware stuff: http://www.writersdigest.com/articles/harrigan_software.asp
Back in the yWriter end of town, Rough Draft http://www.rsalsbury.co.uk/rd.htm
gets regular use here. It has been recently updated and now it's pretty well my main "brain-storming" note thingy for now - nice and simple. yWriter is has more plotting / scenario-building features, but I like the way everything is kept as simple and as functional as possible.
And yes, it would be great if more of these apps had full Unicode support! I've swapped most of my fonts to Unicode.