see if they actually work or not

I'm not worried about them working or not, they've been in beta for a very long time, I'm sure they'll work fine. My only question is if these will have more RAM and/or faster CPUs so that the guide isn't so slow.

how the DirecTV pricing plans work

This was answered in that linked video clip. Pricing plans are exactly the same as they currently are. In my case: pay the regular Tivo fee that I'm already paying, pay to subscribe to whatever high def channels I'm already subscribing to. And of course, I'll be able to Tivo the over-the-air highdef channels I get for free.

who has to pay for installing a good OTA antenna

I'm sure it's no different than what they would charge for installing any other antenna right now. In other words, it's going to depend on who you buy it from, when you buy it, if they're running any installation specials, etc. Me? I put in my own antenna and it was easy enough to do, and works great to get all the OTA channels I wanted.

But yeah, I'm going to need $999 to come down quite a bit and then also be helped by rebates or sales before I can afford that. I'm certainly not expecting a $99 high def Tivo any time soon, but at least price it closer to my grasp...