Laszlo as an RIA Development Toolkit
Recently "Laszlo Systems (Laszlo Systems)":http://www.laszlosystems.com/ announced their flagship product "OpenLaszlo 3.0 (OpenLaszlo 3.0)":http://www.laszlosystems.com/company/press/press_releases/pr_apr_05d.php. OpenLaszlo is an XML-native foundation for building Rich Internet Applications and technically falls straight as a competitor for Flex.
The good part about OpenLaszlo against Flex is that it is free. But again that may be a misnomer, if you look at their "cost of support (Technical Support Cost)":http://www.laszlosystems.com/services/support/technical_support.php, it will eventually make up for the cost of the application. For 1 year, a standard support will cost $15,000 whereas a Premium support cost $35,000.
The Flex components are still better than Laszlo. Development using either Flex or OpenLaszlo will be relatively easy for anybody familiar with a mark-up language. My personal adhearance towards Flex will be more of the fact that it can be easily tied to Flash Remoting, ActionScript 2.0 (and above).
For any developer or a company in Rich Inter Application Development, OpenLaszlo is another good arsenal for their RIA Development Toolkit. That's it for now, more may come but I won't promise.