Building the UI in Javascript

Its turning point time with release of ExtJs 2.0 My web forms are now looking richer and better then in then in previous generation of applications with thick client swing UI's. Ok its not as easy as working visual studio and .net, this still has the edge, but feel its at the same level now as old style hand crafted swing.

Have Tree, live feed combos ,drag and drop, data grids, validation and dynamic form editing sorted no. Can build and run all my major data entry UI in rich combination of rails and extjs.
Only down side its about 500 line of javascript for a complex UI which dwarfs the initial ruby implementations. This may not have the UI simplicity loved by the a lot of core rails people. But provides the richness expected on the thick client crowd without the pain of distribution and installation of 1000's of machines.

All that really lacking is solid graphics. Would really love all browser to support svg as think best approach would be a mixture of ajax and vector definitions from server. Could go the flash way for this and may well, but like open standard approach if possible.