Cross Domain is certainly occurring, but I don't know if that is the issue here. (I did read carefully the blog post).
With FireFox and Chrome, I can watch with fiddler, and I see that I am returning Access-Control-Allow-Origin from my WCF Data service:
HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Date: Tue, 19 Jun 2012 13:55:19 GMT
However, with IE, I get an immediate array from AJAX of e.ErrorThrown is "No transport", and Fiddler is not showing even the HTTP GET request appearing on the wire. So, even though your blog posts a lot of tricks to do on the server side, if I never see the request, then how am I going to convince the IE XDomainRequest object
(if it is true that JQUERY is not using XMLHttpRequest ) that this request is ok.
It seems that the hack has to done somewhere inside of either Kendo's DataSource, or how JQuery is using the XDomainRquest object.
Or maybe the answer is simpler and this is just some sort of security setting in IE that is rejecting cross domain calls and not firing the GET?
Anyway I also have a Google Map in the Kendo application, so that is showing up in fiddler as CORS calls (maps.googleapis.com)