Xperia Arc Rooted
Well we knew this was coming once Sony Ericsson announced unlockable bootloaders for their Xperia phones: the good folks at XDA have rooted the Xperia Arc.
So if you’ve got ahold of Sony’s shiny new phone and want to crack it open, head on over to this thread on XDA for step-by-step instructions from Bin4ry, the one behind rooting the Arc.
And if you have an Xperia Neo, keep an eye on the same thread, as a root method for that phone is coming soon as well.
via Xperia blog