Well, look at Causecast’s site.

This is done pretty darn well.

What did they do?

1. It’s an attractive page.
2. It explains a bit about what’s coming. Compare to Usable.com, which is launching at Demo.
3. It asks you to join and makes an implicit promise to keep you connected.
4. It gives a way for potential business partners (and others like press) to get more info.

Clean, leaves a good first impression, and promises more info to come soon.

Anyone have a better example?