Region coding on Blu-ray is OPTIONAL, not mandatory
The "dirty little secret" - which is a stupid title for an editorial, runs both ways.
There are plenty HD DVD only titles available on Blu-ray in other countries, often better than the HD DVD.
For example, Buena Vista released Face/Off in the UK - it is not released in North America yet (Paramount - HD DVD only) and the UK version is region free with a high bit rate AVC encoding and PCM audio.
Paramount released 16 Blocks on both HD DVD and Blu-ray in North America both versions with lossy audio - the BVHE release on Blu-ray only in Japan features a lossless 5.1 English track.
Buena Vista released Cinderella Man (Universal) in Japan which is the same region as USA.
All Hollywood movies released in Japan feature English 5.1 tracks as that is the main recorded audio.
Paramount and 20th Century Fox did Titanic. It will be HD DVD only in North America and Blu-ray only everywhere else in the world, likely region free as it is a catalog title and in Japan it will be Region A anyway if it is coded.
You need only look at IMDB to see the disc media rights in other countries.
You will NOT see Spider-man coming out on HD DVD anywhere. It is Sony/Columbia (All media - worldwide)
Underworld Evolution was not Sony all media - in Spain it was someone else which is why it's on HD DVD.
If you want to know more about which titles on Blu-ray are region coded you can read here -
http://bluray.liesinc.net/
It wouldn't take much to find this stuff out - poor thread for someone entitled "administrator"