Yeah I totally agree WAHfan,

 I don't think that thet should get married anytime soon, but anyway I think Danny would be too scared to ask her anyway because of what happened to his first wife and Sarah. I think they would both want to take their relationship slowly if they did get together.

But I don't think that they should just stay friends, not after it's taken soo long for Alice to pluck up the courage to tell Danny what she feels, and she still hasn't said it! It's obvious that they have feelings for eachother even though I don't think Danny realises how much he does care for Alice.