If it's any help, I use Pages for my writing and export to Word 08 for Kindle (to save as html) and for Smashwords. I love Pages, though I know some don't. It's easier on the eyes and its text search sidebar function is great for showing all search items in a manuscript. Plus it now lets me also export straight to ePub and works well that way.
So it's Pages for me and Word for my day job (as a freelance copywriter). I also uses the layout part of Pages to make covers and other promo pieces. I know I must sound like an ad, but it gets the job done on my Mac without having to futz around a lot.
Lots of good options mentioned here though.
Steve