We just launched a new Sencha Touch implementation for our client Pier1.com's mobile site. It features backend web crawling technology to display thousands of product pages on the fly. UI still needs work and we are planning many new features like Geo maps, local storage, e-commerce etc, in the near future. Check it out...speed is very good considering what is happening on the backend. Using Touch reduced the time to market for this project considerably. Not optimized yet for iPad but will be soon. The app is using Touch's new MVC framework on the client as well as a server side MVC framework. Looking forward to Direct being supported in Touch and the upcoming 4.0 release of ExtJS!
Http://pier1.com (on mobile browser)