There is a marvelous 6-part program about the 8th annual International Ballet Festival that was just put up on youtube; it has clips from seemingly all the performances. It can be found by putting in the keywords "Mariinsky International Ballet Festival."
I just saw that and it was magnificent! Why can't they do that on A&E or PBS?
GOOD QUESTION. But there are mitigating circumstances...
1) There is NO A&E anymore, it's all E!, they've forgotten the A part.
2) As for PBS, there is only ONE station in the entire 350 station PBS system that ever produces or tapes dance and that's WNET's Great Performances "Dance in America" ,or rarely these days, "Live from Lincoln Center". (Of course PBS' "American Masters" has done a few bios, and ITVS/POV etc. have shown 1-2 docs over their ten+ year history). But, if it's not on their radar with enough lead time, they don't bother. Also, there are a lot of issues such as funding, broadcast, ancillary, & distribution rights--who gets what %? Mariinsky? PBS? etc.etc.--that would have to have been negotiatiated many many months ahead of time. I too, am regularly disappointed by PBS' lack of foresight regarding major dance performances, but do realise the realities required to produce it as well. And a monopoly is a monopoly, especially when the other PBS stations have no idea or interest.