On the flip side, myspace/aol/etc are still in use.
Things that large don't stop on a dime. I do think facebook is hitting a slowing period, the growth days are long behind them. It's only a matter of time until something new sweeps everyone away. Once that happens it will be the new myspace. Where advertisers don't care to market as much. It won't die but it will become less important, and eventually become irrelevant. FBs push notification campaign shows how they are trying to stay relevant.
Back in the 1990s, movies would include an AOL Screen Name (or something similar, room name or something - but AOL specific) in exactly the same way that movies and other advertisements today specify "like us on facebook." At some point that will stop happening as Facebook loses its shine.
Very true, which is why you should trade regularly. Strictly speaking, you can't win unless you play. In the long run, everything dies, so you have to ask yourself: is $FB a good bet for the next year? next 2 years? next five years?
The only certainty is change.