Here is the list of compatible and incompatible devices

Compatible with PERMANENT root option

Samsung Galaxy S (All variants)
Backflip
Sony X10
Xperia Mini
Droid 2
Galaxy Tab
Galaxy I5700
Galaxy 3 I5800
Droid X
Samsung Acclaim
Cricket Huawei Ascend
Motorola Cliq
Huawei 8120
Hero
G1
Optimus T
Droid 1
Garmin Asus A50
Motorola Defy
LG Ally
Motorola Flipside
Motorola Milestone 2
Dell streak
X10 Mini Pro
Smartq v7 android 2.1
Xperia Arc
Sensation

Incompatible with PERMANENT root option

Desire (requires nand unlock)
Desire HD (requires nand unlock)
Magic (unknown)
Evo (requires nand unlock)
G2 (requires nand unlock)
Archos 70 (unknown)
myTouch 3G (unknown)
Wildfire
Droid Incredible