My thoughts :
Arsenal vs Liverpool
After beating AC Milan, Arsenal has to beat the finalists of last year's Champions League and I can assure you that Benitez's side won't give up that easy. The two sides will meet each other 3 times in just a week, as between the 1st and the 2nd leg, they have to play each other for the Premier League at Emirates. No kidding I reckon both sides to have plenty of reserves on that game
Roma vs ManUtd
Revenge time for the Romanisti, the Italian side have the chance to take their blood back after the humiliating 7-1 defeat last season in Champions League. Can they make it ? In my opinion they can and I will be cheering for them in this tie (if I have any voice left after the Arsenal vs Liverpool game )
Schalke vs Barcelona
I don't think Barcelona is gonna have major problem on defeating Schalke. If the Spaniards remain focused, they won't even realise that they 're missing Lionel Messi.
Fenerbahce vs Chelsea
First Olympiakos, now Fenerbahce Ok, if this ain't a fix, what else could it be ?