A lot of my friends who focus on PvP already have their compositions figured out, their team names ready, and a full bank of honor and arena points stored and ready to spend. Even if you aren't the arena type, Tuesday can mean good things for you. What does Season 4 do for you if you don't PvP? Gold, of course! Profit, profit, profit. With the influx of gear into peoples' hands starting Tuesday, gems and enchanting materials are going to spike in price for awhile. I imagine epic gems will feel this especially, as this is essentially the best gear available to PvPers before Wrath of the Lich King. They'll want to make the most of it.
So whether you play for PvP or you play for Profit, tomorrow means good things. Are you ready for it? Have you done anything to prepare? Do you go through any start-of-the-season rituals for good luck? Burning a Druid-shaped wickerman, perhaps?