I don't think that the iMac will be getting either for a while, it will show up in the Mac Pros first, but I would hope that they wait until one format is dead, or there are players and burners for both.
why can't it be an external drive like the xbox 360 HD DVD addon? I would love for Apple to release a Blu Ray external drive for around $200- that way I'll have both formats- (The 360 HD Drive only cost me $127- I love it)
Do people want HD DVD or Bluray for movies or is it for software (games)???
I'm going to be optimistic and say they make a stand in the industry, they include Blu-Ray. Of course we know that they are in the Blu-Ray camp, so I wouldn't expect them to ever have HD-DVD. Though I'm sure they would offer support for the pro applications to produce whatever format you might need.
Apple is innovative, that means that they will want to be one of the first computer manufacturers to start shipping Macs with Blue Ray capability, and it's obvious that Blue Ray has beat HD-DVD on every other market. They day of the CD is dieing closely followed by the DVD.