Need some basic advice: Which element for bow?

I have a very basic question: what are the pros and cons of the different elements for the bow build (for a marauder...but I suppose this isn't exactly marauder specific)? For single target, I'm thinking of using elemental hit, but for multi-target most people seem to be using Lightning Arrow. What about Ice Shot or Exploding Arrow? Or, in the case that they aren't as strong as Lightning Arrow, might there be any indication that they will be buffed?