D&C 59 v. 15 encourages a glad heart and cheerful countenance, but not ‘much laughter.’  WJT points out that this verse is specifically talking about ordinances and sacraments.  The implication is that some laughter is fine when performing ordinances.

That is the gospel I know.  I was recently down at the temple with family at a sealing performed by an old family friend.  He smiled a lot and laughed some and so did we all.

A gospel like this I am compelled to believe.

One of Our Favorite Poems, introduced to Us on this very blog, is Nothing in Heaven Works as It Ought.  That captures something real about heaven.  But my actual image of heaven is some combination of impossible blazing glory and genial garrulity out on the front porch.  Somehow the combination makes sense to me.