I found this interesting(updated emmerald's list):
Mitigation: http://www.emmerald.net/Bear_Mitigation/Neck.html
High-Gear Mitigation: http://www.emmerald.net/Bear_High_Mitigation/Neck.html
In the high-gear list, the Necklace of the deep is actually rated above the SSO pendant. The list gives mitigation values based on HP added and dodge rating. Previous to the patch, the SSO was higher on both lists. This of course, is a list for mitigation and doesn't take into account threat generation issues. I just found it interesting that the NotD moved higher. Seeing as how it's a relatively cheap piece of purchasable gear, it's pretty high on the list.
PS: I believe the difference between the Regular and the High-Gear lists are that High-Gear assumes you are crit immune. Since all feral tank druids are now crit immune, you should go off of the high-gear chart.
Also, the proc on the SSO neck piece has an internal 45s CD that starts when it procs. This means that for every 10 secs of proc uptime, there will be at least 35s of downtime. Rounding up toive 40(gives 5s to obtain proc), this means that the proc is up for around 20%(10s/50s) of the total time which averages to 2% expertise or 1% dodge throughout a fight.
Edited, Nov 12th 2008 3:45pm by jeffoncom