My hosting provider send me an email today informing me that ASP.NET AJAX 1.0 is now available to all DiscountASP.NET customers. I guess I'll have to put some AJAX in my site, just because I can

The message did contain an interesting warning though:

Microsoft officially released ASP.NET AJAX 1.0 and we have installed AJAX 1.0 in the webserver GAC.
(More Info | KB Q10460)

Note: Microsoft has yanked out some features from the AJAX RTM and used the same version number for both v1.0 and the RTM. If you built apps with the RTM, they may not be backward compatible.