Enhance Shamans; how necessary are they?

I've been playing as an enhance shaman since level 10. I must say that I thoroughly enjoy the spec. However, from what I've heard, we really only need one at max in our raids to twist totems in a melee DPS group? My shaman is level 36 and leveling seems to be slow going. I was level 35 for nearly three days... I'm going to be grinding some SM hard this week and will hopefully get to level 40. Then there's getting to level 60. I'm going to need all the help I can get. I know we have Shamans at 60 already, so I guess what I am asking is, would you guys even wait for me or would I get replaced by another shaman before we even get to raid day? Just a few weeks to go, and I am making getting to 60 a top priority.

Get thrusted, Nerds.