Odds of Getting In
Depends on what you mean by the phrase "getting in." Technically, as soon as you trade real money for plastic chips and sit down at a green felt table, you're in. You can even be a part of a satellite tournament to get into the WSOP Main Event for a relatively small amount and have the time of your life getting whooped by the real pros.
But if we're talking about it in terms of getting into this game as a full-time source of income, we wouldn't bet on it. Even if you've put a lot of time and effort into honing your skills and have experienced a lot of success at low stakes, you'll still need a lot of luck to actually make enough every year for housing, car payments, bills, food, cleaning supplies, toothpaste, health care, and the various jams you indulge in (we assume).
It takes a highly skilled and dedicated player to advance beyond this level. Your odds of clearing $100,000 or more a year verge on the miniscule.