Thanks for all the great feedback! We are hoping this will inspire others to do their own broadcasts.
From a technical perspective, it's not that difficult. We used GarageBand (which comes with every Mac) to record and mix it on a MacBook Pro (but any Mac will do). For this particular recording, we used a high end USB mic, but we have used the built-in laptop mic before too, and the audio quality is fine. For the sound effects, we used tracks from the albums "Sports With Balls! Surround Crowds - 4", and "Sports Basketball Sound Effects". You can find both albums on iTunes, where you can buy individual tracks. We cut one of the tracks to create a "crowd loop" that we laid down under the whole broadcast, and inserted the other tracks at the appropriate moments (fouls, substitutions, big plays, etc).
The hard part is the logistics.
First off, if you want to do a two-man booth like we did, you have to find someone else local that is nerdy enough to want to do this. Generally speaking, that is only going to be a fellow HD coach, and I don't know how many people know other coaches that live nearby. Of course, you can announce a game solo, but it's not as much fun, and the color commentator gives the play-by-play guy much needed breaks to prepare for the next sequence (and vice versa). Also, it's easier to set up jokes with two people. I imagine it's possible to record with two people over the internet or a phone line, but I don't have experience with that and am not sure about the sound quality.
Secondly, because nobody is going to be excited to listen to a game that happened a couple of days ago, the broadcast is ideally done right after the play-by-play is released. But even if you live on the west coast, this means staying up into the wee hours of the morning. Another possibility is to record it first thing when you wake up the following morning. Either way, what we have traditionally done for our in-conference broadcasts is email/sitemail the coaches whose teams are playing the game to let them know a broadcast is coming. That way, they can avoid looking at the results of the game, and experience all the excitement and suspense of a "live" broadcast where they don't know the outcome. We actually did this for dedelman and spottratz for the championship too.
Thirdly, because HD play-by-plays are pretty sparse (they only list the end of the action), the play-by-play announcer has to make up all the filler (ball movement, action off the ball, etc) on the spot. This is tricky, because you want it to sound smooth and rapid-fire, as if you are actually watching and describing a game, not trying to think up imaginary basketball action ("he dribbles around, and uh, ummmm, uhhh, he passes it, and uh..."). But you also don't to sound too repetitive, describing the same couple of basic sequences every time. We definitely need to improve in this area.
Lastly, I would recommend doing some preparation. Printing out two copies of the play-by-play, so the color commentator can follow along anticipate where he needs to comment is key. Also, printing out copies of the box score for postgame discussion is helpful. Little things, like figuring out the team mascots, or what arenas they play in, or gathering a few facts about individual players ("he led the conference in scoring this year") can create the sense of a fully realized broadcast.
We broadcast the entire game because it was the championship, and it was the first time we had released a recording "to the public". But most people, aside from the coaches who are playing, are not going to want to listen to a whole game, especially once the novelty wears off. So if anyone is planning to try this, I would recommend broadcasting just the last ten minutes of the game. That's what we have usually done, and it's plenty of action, including the finish, which is usually the most exciting part. The nice thing about being able to see the results before you start the broadcast is that if one team is leading by 15 with ten minutes to go, and it never really gets closer, you can skip it and wait for a more exciting game. :-)
Anyway, thanks again for all the nice comments. If anyone has questions about how we did something in the broadcast, feel free to post them here or sitemail me directly.