Yeah I realize that. I think it's best to wait and see what they do for RTM with this. I was reading somewhere on Twitter they might be even replacing the default JSON Parser used in Web API too. Hopefully they expose more stuff to make it more usable.
Either way, this demo was modeled after this blog post by Stephen Walter:
He mentions at the bottom using $top and $skip to implement paging. I'll play with it more when I have time. Thanks for pointing out to this paramterMap override thread. I was looking at the parameterMap last night myself but was too tired to dissect parameters last night.
Adding a 'webapi' type to the DataSource though would be a great solution if you can get basic paging, sorting and filtering working. Even if there are limitations, if the core stuff works, I think this will be great in the end. It'll make building apps with Kendo and Web API so easy and fast. Well other than trying to use it as odata source, everything else works fine when treating it as plain JSON. If we can implement paging, filtering and sorting using some generic way using parameterMap override that should work too in the short term.