If you need someone to help you develop something like this and you need something ASAP, let me know.
David's Classipress system is by far one of the most innovative pieces of work for the
WP CMS. Off the top of my head, you could build off the Classi-core and structure groupon utilizing:
1. Fb-connect and email lists to keep people informed
2. Usermeta fields and most likely a new table entirely to arrange user information to relative information (ie: you are from "Boston", defaults to Boston sites.
3. A post voting system that is re-integrated as a buy now option.
4. Gateway holds ( Paypal API maybe) that will take up funds once voting condition is met (ie: 150 buys ).
5. Front-end form for businesses to automatically set up their groupon.
Nonetheless, real excited to see the app themes at their best.