I really like flashy-ness and feel that I have run across a bunch of cool sites on the web. One thing that never surprises me though is running into security holes and vulnerabilities… Especially when I get to see the code from someone’s site. When it boils down to it, that a developer can have a widget update several counts at the same time to enhance functionality to a user OR the developer can make a call back to the server to see if a username or keyword is available, doesn’t mean that the developer is super l33t.
The ability to build a solution that works inside and out, completely answering the business’ needs is a more valuable trait of a senior developer than any of these things above. Maybe when you’re interviewing or discussing with potential team mates; mentioning the flashy coolness of AJAX is worth a shot, for small talk. But a more important conversation about answering the business needs with a subset of functionality that does what the business wants it to do in a robust way is more beneficial.