Regen is a great bonus and as mentioned always on. Comparing Troll regen vs Fungi though is worthless. Can use both and will be using both if you can. Regen races are the best healers/support, I have pointed this out in some of the other race debates. Frontal Stun Immunity(FSI) is for soloing or raid slowing.
Of course you can solo and raid slow without FSI, but if you are say soloing a summoning mob that regen is not going to outpace his dps. You will have to cast spells(slow,heal,dots, epic) and if you properly put your back to a wall you will be getting the benefit of FSI a-lot more then 1 out of 100. Epic dot is slow, really slow FSI reduces interrupts which allows you to progress to the next spell. All Shaman worth their salt have the next 5+ spells planned out and are just waiting for the previous spell to end to start their next action, we are always busy and have something to do 5 seconds ago. FSI allows us to stay out of a position to die more so then saves us when we were half a second away from purple healing. The point is to stay on top of the mob and your actions and not fall behind or lest you die.
I still would recommend Regen races to any Shaman that does not want to Face-tank the tough stuff in Kunark/Velious, or be the main slower on a raid. But for anyone that does want to do those things go OGRE. I did the above things as a Barb on live so you can do it with any race, but I really did regret not having that FSI, Regen as well but more so FSI.
[You must be logged in to view images. Log in or Register.]