Adjust, many thanks for this post.
I currently have an eReader (an iRiver Story) that operates on the ePub format, but I'm growing disillusioned with its shortcomings and lack of ongoing development, and am considering jumping ship to Kindle (even though I really don't like being corralled by Amazon). So I've started checking out the options for the .mobi format.
I've been using InDesign for layout and saving directly to ePub format (and then using Sigil to countermand some of the mindless formatting assumptions Adobe makes) ... so finding a direct option for creating .mobi files is exactly what I was hoping for.
Really appreciated, Adjust.