I heard this in one of the #GTD podcasts that seems like a good idea:

If there is some decision you cannot make, then rather than agonizing about that decision frequently, park it into a reminder system for whatever time later that you think you need to think about it again - and don’t think about it again till then.

If you trust this reminder system, this can be an effective way to move that thought/decision out of your mind until some time.