Regarding all that AJAX ("Asynchronous JavaScript and XML") hype that spread around lately (which came along with a new kind of web applications, see GMail, Google Maps, Flickr and the like) I wonder whether server-side gui-event processing (e.g. as propagated by ASP.NET) has come to an end, or if both approaches will co-exist side-by-side in the future. To me, AJAX seems to have some clear advantages on the user-experience level. On the other hand, AJAX denotes an approach, not a standard, so the question arises which AJAX base library to use.
What's interesting to note is that probably the main technology enabler for AJAX was the introduction of the JavaScript XMLHttpRequest class, which originally came from Microsoft (ActiveX's "Microsoft.XMLHTTP"). Mozilla, Safari and other browsers followed with more or less identical implementations. Another proof that - yes indeed - Microsoft DOES innovate.
For me this means to revamp my somewhat dusty JavaScript knowledge (JavaScript 1.2 was were I stopped - enough to do some simple client-side stuff that did not require server round-trips, and was available on all browsers - but certainly not enough for building AJAX applications).