I know it's a spec in bad repute among a lot of raiders, but I run a combined bearkitty spec (one spec for bear and kitty, and I just swap gear). I enjoy it, and the groups I usually raid with love having a viable emergencytank (I gem agi, so I have as much mitigation and avoidance in bear with dps gear on as I have with tank gear- just lower stam). Have saved raids from wipes many times.
From the kitty side, I'm gimping my dps by not having Master Shapeshifter, by gemming agi instead of arpen (though this might change with T10), and by having to share glyphs with bear.
From the bear side, I can get almost everything I need, except infected wounds.
Anyway, I'd like peoples' input on exactly how much I might be gimping my kittydps, and on whether you see any possible improvements to the spec. Depending, I may make my second spec kitty-only or resto.