1) Leave it as it is now in beta 0.2, with 100% absorption and double damage to mana. Keeps you alive much longer and allows you to ignore poison and burning effects... but at the moment my sorc has 7240 mana and around 800% mana regen, so against the smaller critters I never die...and also, without Vit to put points into and with Dex being useless and Str mostly useless (as a sorc, you cannot reach the Marble series of +Def%, +requirements and the Dreadnought style runewords-that-will-become-uniques-in-beta-0.3 anyway) all points will go into Ene resulting in extreme amounts of mana and with high Warmth + Tranquil items (+Regen%) and maybe Meditation from a runeword-that-etc, recharge rates of 500 mana/sec. Even Faith does not regenerate that much health, that quickly.
Also, the skill suffers from the phantom hit bug that causes me to lose mana whenever a monster swings and misses. A lot of time will be spent running with monsters in pursuit, so constantly losing mana by them swatting thin air is not good.
2) Turn it into a temporary invincibility spell, with 100% absorption and 0 damage passed to mana. Duration could go from 5 frames at low levels to maybe 4 seconds at top levels (80+), and with a timer of 10 seconds it would make the spell into a nice panic button for those 'oh sh!t' moments when you get cornered on a rampart with two siege beasts blocking the exit and four imps infernoing you to death.
Downside is, the spell needs a timer to work, and that would preclude the use of a timer on just about any other sorc spell (including firestar and teleport) and also cause problems with other characters like elemental druids who use a charge of it to keep themselves alive through Diablo's flame nova and suddenly find themselves with both skill buttons locked out for ten seconds. Same with necros and poison nova, etc.
What would you do? I really cannot decide... please help!