Can anyone tell me if HD DVD's are divided up into regions like DVDs ?

And if they are, how strictly are they being enforced by player manufacturers ?  (DVD players these days will pretty much play any region)

Thanks!

Mark

PS.  No comments about Blu-ray being better/worse .. just interested in HD DVD at the moment since the Xbox 360 has a drive coming, and HD DVDs are supoposed to be due out soonish in NZ :-)