If I were you I would launch outside of the US, where everyone uses mint and go for uploading of CSV data. That is since the banks hate to allow API access, people muct manually download their data, then upload it to you.
Get someone to do that and put effort into categorising, and you should be on a winner.
Other notes:
1. SSL as someone said
2. The picture is crap - really, it is a pixelated image (so you did not take care over it) it is some J Random clip art, and it is aimed at precisely the people who will least be interested in a personal budgeting site (teenage ravers who run their budgets online, there is a bigger market for former-hairdressers of the First Ladies)
3. I dont really get what I will get if I sign up, and I dont really want to - whatever Internet sixth sense I have tells me signing up is a Bad Thing.
sorry.