That much will get you a sweet, light, mid-to-lower-high-end XC hardtail. I bought a Specialized Stumpjumper for $1100, put in another $500 in accessories (clipless shoes, camelback, multitool, spare tubes, misc. junk) and started riding. I've put in about $700 since then due to upgrades (eggbeaters, ergon grips, new saddle) and breaking stuff (Mavic wheelset). I have some more sunk from making it work with my life (wall bike rack for the living room).

So, be wary of what you spend. Factor in everything associated with the sport... your $2,000 budget may be only 2/3rds bike if you're not a cyclist already.