I'm not a lawyer either, but you bring up some interesting points. I don't believe that replacing ads with Tivo's own ads would constitute fair use because Tivo would be receiving income without compensation to the Intellectual Property owner. But getting to the issue of pre-roll ads, your discussion reminded me of the earworm MLB disclaimer that ran before every baseball game I would listen to or watch while growing up:Hmm. I'm not a lawyer but I really do wonder, under the current fair use law that allows consumers to record broadcast TV, what would preclude TiVo or any other company -- that operates independently of the broadcasters and cable TV operator -- from completely cutting out the original broadcast ads and replacing them with TiVo's own unskippable ads. (I'm not saying that this is what TiVo is doing or will do, I'm just wondering what aspect of current law might preclude such behavior.) Seems to me that if the consumer didn't like that aspect of TiVo's DVR service, it would be up to him to switch to a different DVR service. And I can't see how the broadcasters or cable companies involved would have any legal leg to stand on. But then, as I say, I'm not a lawyer and I don't know all the ins and outs of the applicable law.
"This game is authorized under television rights granted by Major League Baseball solely for the entertainment of our audience and any publication reproduction retransmission or other use of the pictures descriptions and accounts of this game without the express written consent of Major League Baseball is prohibited Any commercial or other use of the program such as by charging admission for its showing is similarly prohibited unless authorized in writing by Major League Baseball."
It strikes me that what Tivo is doing here with its pre-roll is basically charging admission to view IP that it hasn't paid for and has no agreement with the IP owner to retransmit. This could be why Tivo allows skipping of the pre-roll: "We're not charging admission, we're just asking for a donation!" The opt-out (by skipping) nature of the ad could be problematic if Tivo were taken to court on this issue which might require changing to a more opt-in type selection. And Tivo agreeing to a global opt-out (via telephone call that others are reporting) should do the trick.
But then how would Tivo make money on this?
Pure fun speculation on my part since I have no IP experience at all.