Before you get excited, I haven’t got it, but I have found the first page of it here. I tried searching for the original title “я очень рад ведь я наконец возвращаюсь домой” and ноты (sheet music). The page I found came from a Russian sheet music site called true-notki.ru which has now closed.
Surely someone has published this? To any Russian music publishers out there, you must be crazy not to just get off your butts and publish this. Someone gets to my site by searching for ‘trolololo sheet music’ nearly every day.
Update on Christmas day (25/12/11):
Just in time for Christmas, someone has put a link to the file in the comments below. There’s also, I’ve discovered, another link to the sheet music for the Trolololo song here. All not really above board, so my question remains: why doesn’t a mainstream publisher publish it on the mainstream as a digital download? I reckon it could have made them millionaires by now.