It's really not that bad to go from InDesign to ePub. There are a lot of tweaks you have to do, but you can get a pretty good book out of CS4.
In fact, it may be useful for people to get a better idea of what goes into making an epub, so here's some resources:
http://www.adobe.com/products/indesign/epub/howto/
And here's a presentation from Liza Daly called "Getting Past Good Enough" which really talks about publishers' ebook issues, and how it takes actual work to make a good one.
http://digitalbookworld.com/2010/get...oks-liza-daly/