Fear is my biggest concern, but there are a few solutions
1) I have my pvp trinket hotkeyed and it's a 2min CD
2) I have anti magic shell, which gives me fear immunity for 12 seconds - 1 min CD
3) Death and Decay on top of me almost all the time which means that it's REALLY hard to go in and fear. When they do, they usually get effected by cower, not many are brave enough to charge into Death and Decay
4) I am leveling with my shaman with my 4x DKs, anytime I hit my follow key it puts down a tremor totem (unless I am mounted) It's only 48 mana for a tremor totem

Honestly, in normal PvP, the trinket is fine for 80% of cases. Once you blow the trinket, I go for the person who feared me and kill them first.
And if my trinket is down, and I see someone who can fear is close to me, I'll usually blow anti-magic shell which mages me immune.

I'm a bit worried about Arena though, if it turns out to be a big problem, I might have to roll with a shaman for tremor. Although I do have a few outs, so it's not as bad as other classes.