http://www.youtube.com/watch?v=bvDLBom4bY0
Iv also posted numerous videos about shaman tanking. Though i do not recommend rolling a shaman for a main tank class, I tank maly/emalon every week. I practice in heroics every day due to the difficult nature of holding threat with strength tanking accessories. I rely heavily on misdirect classes for aoe pulls because shaman simply dont produce enough aoe threat to hold aggro. With practice however, shaman do have the ability to tank 5man heriocs and 10mans better than any mediocre geared tank in t7. In 25mans and ulduar the amount of self heal and absorb the shaman brings does not make up for the obvious lack of avoidance (where in 10mans and 25naxx a critical heal can make up for an entire hit taken, a stoneclaw absorbs half to 75% of a hit).
to see what a shaman can tank go here http://www.youtube.com/user/sharicasmi