Just watched it and i actually really liked it. Not much of a Will Ferrell fan but this might be his best work since Anchorman. It has loads of cameos by actual Eurovision contenders, but the songs they "parodied" were what made me laugh most.
The song they sing in the end borrows heavily from the song the Netherlands won with last year, they had that Lordi copy in there somewhere and even that viking song is something that actually happened. "Ja Ja Ding Dong" is probably a play on Teach-ins "Ding-a-Dong" the Dutch group that won in '75.
Will Ferrell and his team really did their research, i laughed my ass off.