My shammies are 42, enhancement specced. DW + Windfury = walking tornado. It's a sight to behold. And with totems, things are just sick. Cleared RFD at 40, which was about +5 to the trash and +3 to the bosses, and had no issues. Gonna try uldaman tonight at 42 and see how it goes. Casters are cheese with grounding totems and melee are almost cheese with 5x healing stream + str/agi/AF. :P

[edit]
My biggest thing I love about 'em: zero downtime. Sub-30 (i.e.: pre-windfury) they were sucking pretty hard. Couldn't kill 'em but they took forever to kill anything else. Nice being able to take down +6 stuff, though.

The few experiences I've had in PVP lately have been over in seconds. They'd die without me ever having to re-/follow the alts. /rofl

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Oh, and regarding /follow and mob positioning issues. With shammies being basically auto-attack plus Stormstrike every 10 seconds, positioning is not a big deal at all. So much so that I'd not worry about it. For rogues, this is different due to positional styles.