ednbarby,
I find it interesting that he seemed much more comfortable when Jake was there with him on Oprah, or perhaps it was the knowledge that Michelle would be joining him, too?
Good observation, and I'm sure a common one. Notice how Jake consistantly included Heath in all of the exchanges with Oprah, waiting for Heath's response, kind of encouraging it, and not just grabbing all the attention, which he could have done knowing how reserved Heath can be. Jake strikes me as a bit of a care-taker, very sensitive to other people's feelings, and another reason why he may have been so believable as Jack Twist.
And as you say, Heath is so "humble, loveable, and profound when he gets around to letting it all out.
Too bad Oprah isn't into doing in-depth stuff, could you imagine a comprehensive hour or two on Brokeback Mountain including topic's from the making of the movie to the cast, crew, awards, response on the internet and all that navel gazing?