Fiscal cliff is effectively all the tax increases and spending cuts that should revert back next year.
Right now you are paying less in taxes.
Bush tax cuts, capital gains, defense budget sequester (this will be important for investment options next year, risky though will have to play by ear), alternative minimum tax, Medicare surtax... Tons of legislation.
Ignore the "$7 trillion" number wing thrown out there. Any time you try to size up a ridiculous thing like "the entire economy" or "oil left in the world".. It's just going to be guesswork.
With that said, for educational purposes the fiscal year end is September for te government, they haven't figured out what to do still (November) and everyone is just speculating.
Would bet that people earning more than $250K will be hit in the future. Would make a smaller bet on the dividend laws being changed (buy triple tax free muni's for a trade) and would not be making bets on all the other promises.
Anyway feel free to comment or ask questions.
Good luck guys