Hello Ben-
Kendo UI is very different from Silverlight or other Microsoft solutions you may be familiar with, so some of the concepts don't map 1:1.
The Kendo UI DataSource is useful for querying and binding to all variety of data (XML, JSON, JSONP). The DataSource engine is very efficient at sorting, filtering, grouping, and otherwise working on data with JavaScript. Using the DataSource, you can quickly and easily bind to local or remote data and apply the desired shaping.
At this point, we don't have plans for a query engine, per se, but we will continue to evolve our story for data as it makes sense to help JavaScript app development. Hope that helps.
-Todd