as a publisher
I want to be able to provide potential customers a free/trial/lite version of the application
so that i can allow customers to try before they buy

Allow upload of technical, marketing and end user documentation for solution. Also you could have this as a category

As a microsoft online user, I currently have to check the install on tutorials/solutions to see if they work with a hosted, slimmed down version of sharepoint. More than just microsoft host these - you need to distinguish when solutions require server install easily so I can save time when looking for apps. Thanks!

Unless these features will be here it makes sense to just leverage the other platform for it's purpose of maintaining/managing reviews. :)

I would also love to see clearly which apps are most popular etc.

As I have personally have experienced, users don't always read the description. I deployed the SimpleCMS on a nonBPOS server and naturally got the error message.
If the different solutions had icons showing compatibility with the different server and SharePoint versions, it would spark my interest and I would have seen the non-compatibilty. I think this would be a really powerfull addition. Users could instantly see if a solution will be compatible.

This includes training, consulting, and any offerings. If it's not an App then it shouldn't be on here. Otherwise I am worried credibility may be lost and the purpose/usefulness may diminish.

You probably have this in some charter/rules for the Appstore or rules for how you evaluate products for the Appstore, but it's important.

When you first visit the site it isn't entirely obvious what is on offer and how it works (the word 'SharePoint' doesn't even feature on the homepage). I think the site needs a page explaining who this is for and what is on offer. The page should also explain how the install functionality works including the process for installing apps on internally hosted SharePoint sites. At the moment all you get is a download with a bunch of files and no instructions on where these should go.

as a publisher
I want to be able to contact people who have purchased my application
so that I can advise them on upgrades, special promotions, discounts or new products