There are Blu-Ray burners, both internal and external. You can check prices at
OWC.
Toast is another alternative, cheaper than CS4 (since you can't just buy Encore solo) but not as sophisticated. I think the big drawback right now is that Blu-Ray discs will not play at all in OSX because Apple has not licensed the HDCP copy protection that is required for Blu-Ray. Steve Jobs called it a "bag of hurt," so until he thinks otherwise you won't find BR authoring in any Apple apps.
And Apple is notoriously secret about what new features will be in upcoming software, so it's rather pointless to ask about the new DVDSP here. We'll all find out (hopefully) at NAB in April.
JK
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SCQT! Self-contained QuickTime ? pass it on!