My ad network, supercpm, is still looking to add publishers to it's beta program. If you have a site that gets decent traffic, mostly US traffic, and is not a proxy or forum based site, you can apply now. Check out my sig.
Your site doesnt really tell us about the program. Can you provide more info as in what type of products and companies would be advertised?
At the minute I wouldn't qualify as only about 55% of visitors are from USA, with rest being UK, Canada, Australia ... and then numerous other countries now and again. One thing though is that more infomation should be available as it could be useful in time, maybe as alternative adverts to google if other formats become supported and can also work alongside google adsense. This ability would be crucial to many large traffic sites especially, and usefulto other smaller publishers.
We have a wide range of advertisers from dating sites to smiley downloads. The usual fair for CPM network. These ads can run alongside adsense at any time since they are banners and not contextual. 55% US traffic will do so long as the site is not forums based, or a proxy.
I would suggest creating a more professional looking website. One intro page and one application page does not make an impressive website.