It can be, yes. The UK are on a different HD standard than we are. The UK system is using the same framerate (25fps) as the analog PAL format and the US went with a 30fps rate (the same as NTSC), so these incompatibilities still exist. Some R2 BluRays are encoded at 30fps anyway if there's a perception that a significant portion of people in NTSC countries would buy/import the titles (some, but not all, BBC titles are this way), but since there's already a US release of this planned, I have some doubts that Network would bother encoding their discs to a non-native framerate that will have to be 'standards-converted' in UK viewers' players. All I'm saying is, don't get your hopes set too high until there's more info.