In its own little way, perhaps this bit of propagandizing is as much demonstrative muscle-flexing as the rape of Georgia itself. For as Europe's dependence on Russian petroleum has convinced Putin of his local invincibility, so perhaps arts organizations' reliance on Russian talent, attendance, and support will keep them from responding to this grossly -- and offensively -- political gesture.
Gergiev no longer has any official position at the Met (his tenure as Principal Guest Conductor ended with a concert this spring) and as far as I can see has not been engaged for any of this upcoming season's performances. But it will be interesting to see what, if anything, other companies do.
(It will also be interesting to see if the Russophile trolls that have flooded blogs since this war started will leave their droppings in the comments here.)
UPDATE (8/26): As for what actually happened...