The spike was caused by Bitfury as others has said. KNC most likely will be using our pool information from our accounts when they test our units. Just monitor the forum for post from any of those Day 1 and 2 orders. They will be the first to see activity in their pools if KNC does this
So, is the implication that KnC will burn-in our miners using our BTC payout address and preferred pool? That might work with Eligius given that no password is required but not Slush's.
No, you can enter a worker name and worker password, but they don't currently have a free-form URL field You have to pick from one of the options they give you. Slush is on the list.
However, I would not use slush if I were you, you don't get paid fully unless a block is found while you are hashing with them for at least 10-20 minutes, and you don't get anything unless a block is found within 20m of you stopping hashing (and almost nothing if it's more then 5m after)
Go with a pool doing a PPLNS or PPS. Eligius will give you the most interesting stats, but you don't have control over payouts.