It's just been announced at blizzcon! As a fellow vanilla fan, having the frustrations in the drama of all the private WoW Vanilla servers up and down and changing names every few months has been annoying.
I personally thought it was a matter of time until Blizzard realised that they are missing out on 10k a month subs (going off Lightshope population daily) by being stubborn and not running vanilla servers. Their trash over not being able to do it was always tosh and I'm glad they will be supporting them.
I'd gladly pay £10 a month for vanilla as I really enjoyed it and enjoy the trip down memory lane and this day and age, £10 for 10 hours of fun in a game is a cheap price to pay!
I didn't find the right solution from the internet.