New Neighbors

Someone bought the house next door to me for only $132,000.  That is way less than we bought our house for 3 years ago.  This house is pretty much the same as ours except for the fact that it needs a lot of work done.  Anyway, a mom bought it for her son (nice mom).  And nobody has moved in yet but they have been out working on it almost everyday.  I was all set to go over and meet them yesterday but they didn't show up to work on the house.  I don't really know any of my neighbors and I heard these ones have a 2-year-old daughter.  So I am hoping we can be friends.  They also have been cutting down branches off of a large tree in their back yard and I wanted to ask them if they can also cut down some of the branches that hang into our yard.  One branch fell down yesterday when they weren't there and almost killed Bob.  Seriously, he was mowing the lawn and a huge branch fell on the lawn mower.  By huge I mean the diameter of the branch was probably about 5 inches.  Definitely large enough to do damage if it lands on you head or a child.

Basically I am trying to figure out how to get to know my neighbors who haven't moved in yet and ask them to cut down their branches at the same time.  I can't really just talk to them through the fence or anything, I would actually need to walk over to their house to be able to see them clearly.  I am excited to have new neighbors because the house has been empty for a while. I will probably just walk over and try to introduce myself when they are outside, but I am pretty shy with people I don't know very well.  Any suggestions?