I've seen this many times and I'm always praying on my knees when it reaches a few critical stages... 59% is one of them.

I've seen it taken about 10 or 15 minutes at 59%.

1) Might be a scan of the disks/volume / e2fsck? Look at the LEDs at the disks.. is anything happening?
2) One time I saw it hanging at (I thought 90%), only after unplugging it from the network (it had 8 network cables for failover, heartbeat, bond, etc.) it was able to boot. At 90 or 91%, the webinterface/Apache is loaded and you should be able to access it.
3) I've even seen it happen after booting with a fresh installed Open-E medium (I assume it was a disk check in that case).

I hope Open-E will make an option to press ESC during boot to actually see all the (debug) messages during boot instead of showing the Logo.