It might help to be an active member of some of those sites first before soliciting feedback.
My project is http://AppRabbit.com, a database web app builder.
Anyway maybe you need to define more clearly what you want? What is a 'passionate' user? Your app doesn't appear to be social, so you don't need to create the illusion of popularity on-site, like reddit. Do you want evangelists, people going out and blogging about how great your app is?
I don't really know how to bring that about. Just make the best damn thing you can and then politely inform bloggers you read about it. If you look at the balsamiq (a mockup program) website there is a post on how the guy approached bloggers at the start.
I quite like the Steve Martin approach: "be so good they can't ignore you". Naively, I kind of think that if you make something great, that really solves a problem for people, they will want to share that with others.
So... I guess the answer is for you to very clearly define who you are helping, what problem you are helping them solve, and then approach them. By way of friendly criticism, your site could probably do with a better front page, in terms of a very quick explanation of what it is and why a reader might care. Some good examples:
http://rethinkdb.com/ http://basecamphq.com/
One question for you to think about (in general, but especially for the front page) would be who would need to implement a database but would not want or be able to do it themselves.
For your project, I would suggest having a no-signup live demo that they can use right away. No one will get passionate about a landing page. That might be useful for gaging interest and collecting emails, but if you can't solve someone's problem on their first visit (or at least make it clear how you could) then it's going to be hard to turn them into a passionate user.