I'm really impressed with how many of you say "first I'll go into practise mode...". I will never have the patience for that.
First, I will watch the full cinematic witch opens the game. Then, with tears of joy rolling down my cheeks, I'll go straight into a standard versus match. 3 stocks, no items and battle field (cause it looks so awesome). Haven't descided what character to use first. Will descide when more is revealed. I will play around like that for a while, atleast test every character in the starting roster.
After finding a favourite I intend to test one or a few online games just to see if the lag is fixed (please god). Then I will play through the single player mode once and then proceed to start unlocking as much as I can during the rest of the day. I will probably "cheat" (really wish I wouldn't, but I wont be able to contain myself) and look online how to unlock stuff. I presume It will involve clearnig a single palyer mode and playing x games with this character and x games on that stage and so on.
When I go to sleep I will bring the smash case with me. My girlfriend might have to sleep on the couch, haven't descided yet if it will be alright to share our (me and the smash case) first night together with some one else.
The next day I will invite over a friend, that is off pretty equal skill level. I will proceed to kick his ass all day using my one day edge of training. Just have to keep the release date a secret so he won't get it day one aswell.