1. Love the design. Simple, clean, effective.
2. The "tools" sections need to be much more apparent. This is in theory the main purpose of the site.
3. 140 characters is hot as Hansel right now, but there's no way someone can pitch me effectively in 140. I think that needs to be upped significantly.
4. I'd like the homepage to be more of a personal dashboard. History of direct contact, recommendations of new releases that fall in line with my "public collections" (I don't like that terminology, 'groups' maybe?), etc.
I focused on the negative because those are the areas I think need the most work, but overall I think you're off to an awesome start. I could see this becoming very usable for me - ie, button on my blog and a note that I will only consider pitches delivered via Ivylees. Man, that sure would help my inbox...