But if you're not pushing a bunch of hypertext down to my browser, you're not helping me explore the space.I agree with this. Nothing about the server should be specific to the client. Adobe promotes FDS (Flex Data Services) and there may be a time and place to use it (or not), but that's not "on the web".
I don't think developers should slide into the mode of piece-wise assembly of a bunch of widgets and wiring them up to the automated updaters keeping objects-in-sync across networks.
But taking a more web-oriented approach doesn't preclude using client stuff that's a bit more expressive than current popular browsers. There're good ajax apps and there're bad ajax apps. Same with other "RIA" technologies.
RIAs built on something like Flex and possibly Apollo, but using the web in the right way is appealing to me. Finding more simple ways to build the RIA part *and* get the most out of the web is an interesting challenge.