We've always had presents under the tree before Christmas. There are usually a few that don't appear until after everyone has gone to bed Christmas Eve, though. The only problem I remember with the presents being out early was years ago, when we still had a live tree, the family cat, Charlie, would splash the water out of the tree's stand onto the presents nearest the trunk. Then there was the year he ran around the house at full speed (interesting to watch and hear, as the floor was linoleum), went into the playroom and leaped into the tree! Some presents had to be re wrapped, and some ornaments didn't survive!