The bookmakers have Utd as a long as 10/1 to win tonight, but they don't need to win on the night to qualify which is why they are lower in those markets, as short as 6/1 in fact.
I really can't pick what's going to happen. There is a Utd team that we've seen sporadically this season that can be a match for any other, but it only makes rare appearances. One thing is for sure, if Utd do overcome the odds and make it to the semi finals then it will rank as one of the great upsets in recent years, and buy Moyes a lot of credit at Old Trafford (both in the stands and in the boardroom).
One more thing to consider, if Utd do win, then it could cause some issues for Everton and Arsenal chasing 4th. If Utd end up winning the competition and finishing outside the top four, like Chelsea did two years ago, then they go into Europe at the expense of the fourth placed team. Couldn't happen could it? Could it?
Plenty of value in the betting (as I've said before, this is why I love English teams staying the distance in Europe) tonight, and some great moneyback specials. I for one will be on them, and wishing Utd well.