I just bought a Roku TV, and am currently exploring the functionality.
I found the ECP documentation, and am able to list apps, launch them etc.
Since my remote does not include a keyboard, ECP search from my computer seems useful.
I tried some of the examples in the documentation, but search does not seem to work entirely as described. Specifically, provider and provider-id seem to have no effect. It would be nice to limit search results to specific channels, or installed ones, or free ones, for instance. It would also be useful to be able to search for video titles within Youtube - the Roku search seems to not return any Youtube results at all.
Also, do any channels actually implement deep linking ?