Hi,
A friend of mine tried to update her iPad2 via iTunes 12 and guess what, it became a brick like mine and everyone else. She brought to the service centre and they told her that the iPad is gone and she need to pay for a replacement. She couldn't start/restart/force start etc.
Well, I found out that even though the iPad 2 in the recovery mode state, your data is still in tact (well, basically everything is still there, apps and all)
Through sheer luck and plenty of sleepless nights, I discovered that if you install iTunes 10.6.3 (do not update to iTunes 12) and attempt to recover the OS with any older iOS (compatible with 10.6.3) the update will fail .... BUT.... the iPad2 will restart and you'd see the iOS with all your apps etc as it was before the upgrade. (Google for iTunes 10.6.3 and iTunes 6 or something.)
Unfortunately, it means that it's still at iOS 4 but it is usable and you don't have to pay for a replacement.
Well, I still haven't figured out how to upgrade successfully to iOS9, gonna try bwttchd's method
Cheer 🙂