(All of the following presumes Voom survives beyond March.)
What we'll see is some sort of "Pack" rearrangement/pricing changes.
The RSNs are last in the expansion because the SportsPack (ESPN HD, FSC, TC, GC, Fuel) will become an extra charge. $10-$15 for this pack may be fair if it includes one's RSN and, say, ESPN 2 HD and Outdoor Channel HD. (And some more SD.) Those who want to pay, can.
You'll probably see the same thing happen to the MarqueePack (TNT, UHD, DHD). I suspect there's a channel add or four waiting to happen here. (Might get some SD too.) Tada: Voom will get both INHD and HDNet.
Fear of litigation will get INHD to play ball, who already has the slogan "The Hi-Def Experience" waiting to replace "Only on Cable." Voom's been pressuring them for a while.
And HDNet? Hasn't the Dolan-Cuban feud been with Jimmy? I found a Jan. 2004 quote from Chuck Dolan about Cuban that was pretty kind:
"It's not going to be the technological difference in their ability to deliver HD," said Charles Dolan. "It is going to be the content. We're happy with what Mark [Cuban] is doing to be moving heavily on the content side into HD." TVTechnology.com
So... the "packs" have always been listed as included in the basic $49.90 package "for a limited time." I think that is about to change, but programming will increase at the same time, so it will be tough to argue with. The $49.90 will be SD+Voom21, and there will be a new $39.90 limited SD tier, with a good (bad?) amount of SD moved to various "Packs."
The pricing will make VaVaVoom more attractive, and it may eventually (or immediately) rise to $99.90, still a good deal for everything you get. This, plus PPV, the DVR, and whole house, is a joint effort to not only increase subscribers, but increase our average bill.