Right, I suggested we use Abrupt Jaunt as a Swift action instead of as an Immediate action. This removed the ability to negate an attack through interruption and relegated it to use only during my character's turn, in addition to taking up a swift action for that round.
Using it in this way over the levels I found tremendous use out of it to avoid close combat and especially AoOs as I could port 10-ft (or "Bamf" ala nightcrawler style, as we called it at the table) away from an adjacent foe, cast a spell, and then take a move action to move further away if need be - all to avoid an AoO or having to cast defensively. In narrow hallways in a dungeon I was able to bamf through a barred gate, cast with a clear line of sight and then bamf behind a corner, cover, or allies and still have a move action to make use of either before or after. Made great use as a hit-and-run tactic as I could step out of cover, cast a spell, and then port back behind cover again.
I even used it to port 10-ft off a out of control wagon and off of a charging mount to escape dangerous situations. Of particular use I was able to jump pathetically 5-ft over a 10-ft wide pit and then teleported another 10-ft to the other side to save a comrade hanging from the edge after a botched jump. My party members thought I was insane but hadn't realized I could port across after a short jump. Since 10-ft is usually enough to get up one story I was able to jump off of a fence and teleport on top of the adjacent building's roof as well as step off and port safely back to the street below. Not bad for a wee little wizard.
We had to remove the immediate action use to reduce the ability's power level but even used as a Swift action this was still the coolest. Ability. Ever. I've never had so much fun thinking of creative new ways to make use of this ability. The only one I never got to try to use was peeking through a large keyhole and then teleporting to the otherside, as the only limitation for the ability appears to be line of sight.