Is your domain HEF?
Selecting a name for your new site is perhaps the most important thing you will ever do. Of course the content and design is important but if no one can remember your name all that time and effort will be wasted.
You'll find loads of sites on the net telling you the golden rules of domain name selection:
Keep It Simple Stupid
Where do you stop. You've got a great idea for an extension but at what point do you say enough is enough and release. There has to be a point in the development of an extension where adding additional features actualy detracts from the effectiveness of the extension rather than adding to it.
If/When you start development on your extension don't reinvent the wheel!
Joomla has established several default behaviours and irrespective of whether you agree with them your users are already familiar with them. By following these defaults you will greatly reduce the learning curve for your extensions and consequently reduce the number of support requests.