Reading the article, it looks like they will be broadcasting WWE Royal Rumble in HD, probably back then WWE didn't have enough equipments to provide HD up until now or maybe they weren't committing into the whole HD thing because not many people had HDTV's back then and probably didn't want to spend the extra money to broadcast it in HD, the WWE audience keeps getting bigger and bigger by the year, and as of now there is a good chunk of people that have HDTV sets in their homes and its definitely worth it for them to broadcast the PPV's in HD.
I would love to see WWE RAW and WWE Friday Night Smack down! broad casted in HD.