I have seen web applications that have desktop look and feel (e.g those done with flex or extgwt) demo. I have also seen web applications (rich with ajax) that have web look and feel - e.g gmail . My questions is: which ones are more usable? and which ones are the future. I am not talking of websites here but applications, think accounting software or Human Resource management Software.
If there is one thing you can bet on, I think, it would be HTML and JavaScript. Nothing is more ubiquitous. Moreover, with HTML5 it looks like you should be able to do almost anything that the other RIA frameworks provide.