The recently released 4.2 version of Nexaweb Server and the complementary Studio 2.2 tool plugs in to Eclipse to build Java applet-, AJAX-, RCP-, and script-supported rich GUIs that reach back through (among other things) Nexaweb's client middleware messaging bus (think of IBM's Workplace client). The combination offers an automated offline work and data capture capability, a data framework, testing tools support, and Eclipse Web Tool Platform support.
The net-net is you can use XML and Eclipse plug-ins for a RAD benefit to RIA and Web 2.0 applications with powerful data presentations. This includes down and dirty data connectivity and rich data views using drag and drop constructs and Hibernate. Hitachi's SI folks are big fans. It's worth a look. (Full disclosure: Nexaweb is not a client of Interarbor Solutions, I just liked the technology.)