"There is no real need to tape the final performance of Hairspray. Harvey and Winouker are already captured on cast album."
This is why it would be great IF they did decide to tape it now.
Usually, if things do get taped, they get taped near the end of the run, when all the replacement members are in, and then we lament that it would have been better to tape the original cast. Now you are complaining that two members of the original cast are back, but they've already been recorded on a cast album, so no need to tape them again?
While I agree that theatre should be best enjoyed live, there are shows that I would like to see in New York, but the expense of going there is often times too great, and it might take a while before a regional production pops up (I still would love to see "Caroline, or Change", but it feels like no one in Seattle is ever going to produce it), so it would be really nice to see them on video, especially if it's closing on Broadway anyway. I don't really see a DVD release cannibalizing sales of live theatre too much anyway. If you are a musical theatre fan, you would want to see it in the Theatre live on stage, even if you have worn out your Angela Lansbury "Sweeney Todd" DVD.
That, and we would have a more permanent record of shows done. Theatre seems like one of the few art forms where there is less of a better record of things done that some other artistic mediums, which leads to only having fuzzy memories and arguments over what has really happened.
Xanadu! Can't cry on cue!