Information source

You may well have heard of these two - I generally find them pretty useful:

www.digitalbroadcasting.com
Very US-oriented, but a good collection of all the issues: from enhanced TV and interactive services, to VOD and PVR. The "News & Analysis" section is particularly good for current events and updates (for more detailed reports and white papers, the e-consultancy database is probably a better way to go.)

www.opentv.com/industry/tvexpert/
A shameless propoganda tool for OpenTV but does include some useful links and updates.

Please post any other recommended sites for iDTV research.