Have a look at the new MapFish prototype which uses Flex technology.
This prototype is a client side application with the following functions:
- Navigation: Zoom / Pan / Full extent
- Layer Tree
- Satistical representation: chloropleth and proportional symbols
- Legend for proportional symbols
- Tooltip with hyperlink
- Higlight feature
We see Flex as an alternative to GeoExt, but Flex doesn’t have currently the power of ExtJS and OpenLayers. We look forward to use OpenScales in a near future in order to create real web mapping applications with Flex.