We were greeted by our neighbours while we were unloading the truck and havent looked back! I was so glad that they made the effort with us rather than going through those 'do i say hi?' moments for weeks/months/ ever..
We had one familt in our crt give us a bottle of wine / another gave us a block of chocolate and another mowed our lawn the day after we moved in - the house had been trashed by the tennants that were in here before we bought the place.

I would definately go over and say hi!