So after reading the paper on this one, your staked sps will go towards how many vouchers you receive to buy the packs pre-sale. You will not be able to open those packs until they become available to everyone.
The more stakes sps you have, the more vouchers you get. You will then be able to buy vouchers or partial vouchers on the market to make up to a whole number if you actually don't have enough sps.
Hope that makes sense.
RE: Staking SPS for Pre-sale???