Honestly, I don't need a ton of features in my eBook reader. Top 3:
1. Wide array of document formats - RTF, TXT, HTML, and PDF being the ones I'd need most often.
2. Far, far less ghosting per page turn than a Sony Reader. I finally got to look at the Reader hands-on in my local Borders and the amount of flicker per page turn was overwhelming. Of course, I think that someone had started playing an audio file and walked away, and after a minute or two with the Reader's interface I still couldn't figure out how to turn it off, so I went straight to the books - this may have been related.
3. Related to the previous anecdote: an interface that is fairly simple.
4. Okay, I lied, so there's four: a note-taking feature. This is the #1 reason why I'd like to eventually purchase an Iliad; however, the reportedly low battery life and the overload of other features are the reasons why I won't purchase an Iliad (well, that and the oppressively high price tag!).
Basically, I need something that will display whatever I want, display it well, let me flip through it easily, and let me take notes (whether on the document or separately). And doesn't cost too much.
I don't ask for much, do I?
(Also, hi: long-time lurker, first-time poster.)