Anyone not currently using teleport is either not playing Inferno (the only difficulty mode that matters), or is using 2-3 other--less effective--defensive skills in its place, and thus wasting time and/or dps. Teleport is a Wizard's only escape spell, and it can be used both offensively and defensively depending on your survivability requirements in your best gear; in Inferno, where nearly every Champ pack or Elite has one or more of Fast/Teleporting/Vortex/Jailer mods and so much CC reduction that snares are almost completely ineffective, the way you actually stay alive in practice is like this: dps while kiting, take first hit through Force Armor (after stacking a lot of damage reduction on gear, of course) to proc Illusionist and reset your cooldown on teleport, teleport to escape/interrupt/dps as needed, then dps and kite while regenerating health - repeat until your mob is dead.
Of course, using Teleport requires the Illusionist passive skill to make any good use of it - but the only other Inferno-worthy passives we have at this point are Glass Cannon/Cold Blooded/Conflagration in terms of offense (Glass Cannon being the only one worth taking in all but a handful of only marginally-effective builds), and Galvanizing Ward and Blur for defense.
(General rule in choosing passives is this, for those unfamiliar: Galvanizing Ward until you reach at least 1200 life regen per second WITHOUT it; Blur until you have enough DR to take advantage of Force Armor or unless melee damage isn't an issue; Illusionist always - because you're always using teleport; then phase in offensives as you increase your survivability, starting with Glass Cannon).
Many people recommend Teleport with Fracture, but I've found that the decoys are extremely unreliable a majority of the time; to make effective use of them, you really need to use teleport before you've caused any damage to a mob, or else the mob will ignore your decoys completely - but this would mean you're playing inefficiently and overly defensively to begin with, and ultimately hurts your survivability by unnecessarily prolonging fights. I find this rune is only effective when fighting extremely large groups of many, many mobs - in which case, a small portion of them may be distracted by the decoys, which accounts for a moderate amount of overall damage reduction. Still, that's almost always an avoidable situation, and manageable in other, better ways.
In such a situation, Wormhole would be a better option - because it would allow you to escape to a safe area/choke point and take control of the battle from there. In my experience, if you need a strong defensive option, Wormhole is just far superior overall; it lets you completely escape a fight with all but those few Extra Fast mobs that are already extremely fast by default, (mostly in Act 2), which allows you to re-engage on your own terms - a far more valuable tactical solution than simply avoiding a single attack. If you're very fragile and simply can't take ANY hits yet, this is your best bet against most mobs and packs.
The Calamity rune is ideal if you have enough damage reduction to easily survive 3-4 hits through Force Armor, and enough life regeneration to recoup the loss from one hit in no less than a few seconds (>20k health, ~90% DR minimum without dodge, and ~1500 life regen per second). The Wave of Force cast upon landing actually knocks mobs back quite a reasonable distance, does decent damage, interrupts any casting/attack animation on non-bosses (though you need to be conscious of your latency when using it in this way or they can still hit you if your timing isn't perfect!), and can be used both to escape a mob's area as well as to simply push it away from your area - a huge improvement over other Teleport runes in general, and even more so when used in the currently top-performing Venom Hydra/Blizzard build variant, as it requires very precise positioning overall and kiting in the same area to take advantage of venom pools. I used this to great effect beginning in Act 2 Inferno, when I found I needed something that would allow me to repeatedly escape mobs that could close any distance nearly instantly and which could not be kited effectively with Blizzard (leapers, etc), without completely stopping my damage output. If you're forced to use Calamity in a primarily defensive capacity for an extended period of time (i.e. you don't have enough time to cast 2-3 other dps spells between teleports), Mirror Image with Mimics are an excellent addition; with the small damage component they add while you're running for your life, plus the damage from Calamity, kiting battles will go much, much, MUCH faster - helping you avoid enrage timers, as well as keeping you out of harm's way.
If you consider the half-second to one second that mobs spend "confused" after being knocked back every time you use Teleport with Calamity, your overall reduction of incoming damage is going to be far higher than with any other rune - AND you're doing damage at the same time. It's basically a Wizard's form of counter-attacking, and it's very effective when you learn to use it expertly.