Since we have about 40% crit with just T7 in raid, Cobra Strikes has about 13/25/37% uptime, which should be a significant dps difference.
As for Serpent's Swiftness, even after soft haste cap, the talent is still a dps increase (granted it's a minor one), while there aren't really alternative dps talents (invigoration is dps boost if encounter is long, but we'll see how long they are before getting to concrete numbers). Also, Serpent's Swiftness ups pet dps significantly (it should be about 5% of total dps loss for not taking it). With just the rough numbers, Serpent's Swiftness isn't really replaceable. As for Cobra Strikes, more math may be needed once WotLK comes out to see if invigoration may be worth it, but I doubt it, since it's too situational.
Couple more things I'm curious about.
Pet GCD. Some say it's 1.5, some say it's 1.25, and I haven't personally tested this to say anything about their tests. However, 1.5/1.2 = 1.25!!! Is it possible that Serpent's Swiftness's 20% haste is affecting pet's GCD??? I'll try testing this once I get home (bah respec...), but it would be nice if others can as well.
Another thing is, how are you people gonna spec bm when WotLK comes out. The general thread is way too long. =P
I was thinking something like
this. I didn't think too hard about the spec, so it probably isn't that great, but any comments/discussion would be appreciated.