I'm talking about the long distance travel ones that are rituals, not the short range ones that players can do in combat starting at first level.
The basic system in 4ed is that there are permanent teleportation circles scattered across the lands. Most are in cities, mage guilds, various temples, etc. Each circle has a selection of arcane marks that are unique to that circle (arcane GPS coordinates). These circles do nothing on their own, but they are the target for the 10 minute ritual that opens a short lived one-way teleportation circle. To link to a circle, you have to know it's arcane marks... meaning either research or having seen it.
In general, these teleports are cheaper if they are cast from a circle to another circle, but can be done from anywhere to a circle.
Linked Portal (8) - Teleport to a circle on the same plane. Same level as Raising the dead.
Planar Portal (18) - Teleport to a circle on another plane.
Forbiddance (20) - Can block teleportation unless of higher level then caster of the ritual. Can be sustained by spending 1 healing surge each day (even if not in area) and after a year and a day, becomes permanent.
True Portal (28) - Teleport without using a circle.
Now on the one side this is a mechanic I find reminiscent of town portals in Diablo, or the Stargate, although not exactly like either. I can see why they did it: No more trouble with Scry and Die until level 28. It also makes for better or easier use with plot points... and it makes teleportation circle designations a valuable commodity. Players will likely have to travel on foot across the country to find somewhere the first time, but can teleport back whenever they are willing to pay the price rather then travel. Joining a mage guild might provide you with the ring codes for circles at each chapter house, making overland travel much faster. Page 156 of the new DMG seems to talk about this in a side bar along with some interesting adventure hook concepts... but it doesn't go into anything in big detail. Where would these circles be? Who made them and why? How might various cities or groups guard them? Do wealthy merchants travel via them or even transport good via them? etc. What kind of wards might be encountered around them?
Also, there don't seem to be rules for making your own permanent teleportation circles (yet.)










