My H also did take some of the stuff in the house I didn't expect: most of the pictures on the walls (they were from his family inherited or given by his family to us in his defense), and if you don't want to prevent that kind of misunderstanding probably good to be there. I don't know, I was advised by others here also to have the kids there and be there at least some of the time so that your W realizes the full impact of what she is doing (leaving her kids). I also think it might be good for the kids to see at least a little of what is going on (your W moving out) so they realize what is going on; you aren't keeping them in the dark and then springing on them after a fun trip or day. My brother was kept in the dark about my mom being sick for example, and to this day is still upset they didn't keep him informed so he would have time to grieve & deal with it (she died when he was 14). Something I like to keep in mind with my kids anyway.
But on the other hand if you will lose it and cry the whole time or whatever I don't think that is good for the kids either. I was able to be just fine and in fact, by the time my H moved out after having the affair for several months, I felt a great sense of relief at H moving out. Helped him pack up and move out quite a bit; and it wasn't as painful as I thought it would be! So I think you have to maybe consider what will be best for you and your kids and do that (which might be staying or leaving). But maybe if you aren't there you could have a family member of yours or close friend or something there to make sure your W doesn't raid the house? B/c I think that could happen even if you don't expect it! Karen