I have an unrooted Verizon Galaxy Nexus, just recently upgraded to Jelly Bean.
One of the touted features of Jelly Bean was the addition of the "Restart in safe mode" option from the power menu. (Long-press power button.)
However, no such option is available. In fact, it's the exact same options I saw under Android 4.0.4 (Power off; Airplane mode; silent; vibrate-only; sound on).
Is there a setting I missed? Or is this really a hardware option for the Nexus 7?