Magic Ajax Panel
So with a simple search I find out that the theory of this magic control is a fact. Its actually been on sourceforge all this time and is being worked on a lot recently. Basically you can take any control [ yes both asp.net 1.1/2.0] and drag it to an Ajax Panel and your control becomes an Ajax control. You also need to add some things to your page to make it Ajax [Make it extend from Ajax.AjaxPage and override a few methods]. The link below explains everything with a good example and sample code. There are also links to the official release and you can judge for yourself.
ASP.NET 2.0 Magic Ajax Samples