Here's a quick demo of the 1.4GHz overclock patches for the Samsung Galaxy Nexus. These modifications should work on both the international GSM and Verizon LTE versions.
Undervolting options also available in this kernel should allow you to save significant battery life. The undervolting interface is identical to that on custom Nexus S kernels.
Some OMAP4460s are indeed rated for 1.5GHz, so I am working to get the Galaxy Nexus faster than 1.4GHz. It's definitely possible, but it's not as easy as it sounds and is being worked on.
Thanks to franciscofranco for testing the original overclock patch, and enjoy!
Test kernel + patches: http://forum.xda-developers.com/showthread.php?p=20062269