We should have packed a while ago
Kepler-22b is located 600 light-years away
space shuttle must reach speeds of about 17,500 mph (28,000 kilometers per hour) to remain in orbit. The exact speed depends on the space shuttle's orbital altitude
Assuming that speed and our magic fuel, we would only need
23,007,827 (Corrected, I am mathing very goodly today) years to get there, better start packing!
EDIT: Oh yeah, Earth-like planets really arn't anything new, I remember hearing about one very, very close to us by comparison: the planets of the Gliese 581
are candidates for this, and they're "only" 20 light years away. Only in quotes,of course, since that'd still take us about 770,000 years to get there at current speeds.
I'm still holding out hope that they'll announce that Alpha Centauri
has habitable planets someday- that would only take a couple thousand years to reach!