When Grizzleheim was released, along with that was a very interesting new feature that allowed Wizards to bamf from a central location out to the further reaches of the zone with a click. THUS, THE TELEPORT STONES WERE BORN! Soon after that it became the new hot sauce for KingsIsle, and teleport stones were put in all the worlds of the Spiral.
If you knew which stone went where, using them was a HUGE time savings. I think the people who benefited most from their use were those who farmed bosses near the teleport stone exits.
There was something awesome about being the guy who knew your way around quickly and could race people to a boss, then you'd send 'em a tell saying "Hey, you still running here? You could have just ported to me like an hour ago . . ."
Anything that's a time savings is a blessing in an MMO; therefore, teleport stones are awesome.