Website looks good (Still waiting on your email - No worries though)
A couple of things spring to mind which other HN'ers have addressed, but I will put my thoughts down regardless
1. Having an iPhone app is great - given the fact that you can take pictures, log your location - but for a large part of my day, I have a full blown keyboard and a 25" screen - and not being able to use that to jot down thoughts defeats the purpose. Everyday.me and Day One get this right (although they both have issues that I will highlight next). Case in point - I need a client on the desktop. Momento, the app that I have been using for close to 2 years now sucks at this, but they get almost everything else right.
2. With regards to having a client, perhaps an API would be nice - one that someone can run with to build a desktop client. I have no issues using a web interface, but Day One gets this right - a rich client, a keystroke away to capture something really quickly. Furthermore, it gives me the ability to post longer - like an end-of-the-day entry covering how I felt, and how I thought the day went
3. Export - I want my entries out of the system. Momento (my current journalling app of choice) gets this right. They give you ways to back up your entire journal, and a way to export your entries as plain text. This is my current issue with Everyday.me (I know they allow you to export entries now, but it's only specific ones - No bulk export capability)
4. Security - This is the reason I stopped using OhLife - I still post once in a while, but all my truly personal thoughts go in Momento. You mentioned that you already have Dropbox integration on your list, and that would certainly be nice. That does not mean I will not post to blobly but I need to know that security is a top priority.
5. Tags and potentially Address book integration - Momento gets this right, to some extent - But tags not only help search better, they provide (at least to me) some context to "group" things together.
6. Multiple photos per entry - Momento gets this right, Day One not so much.
7. Integration with other social networking sites - Twitter/Facebook at a minimum. Momento gets this right. Another one is the potential to hook into an RSS feed (Momento does this)
7a. (Addendum to point no. 7) Here's my approach to it - I export my phone entries, text messages, photos, momento entries, and calendar entries every month. I am working on a script that "stitches" together all this information to give me a full view of what my day looked like. I think for most this would be a little extreme, but getting close to it would be nice :)
With all that said, let me say that your app looks gorgeous, and I can't wait to give it a spin on my phone (once I get my invite :D) - I would love to have a one-stop full featured journaling app on my phone (and desktop). I wish you well - and you can be certain you will be getting some feedback from me - and something tells me, even some money :)
Good luck.