I haven't had any issues with tanking in the 4.0.1 patch. I wouldn't use pulverize on trash, especially since lacerate hits as hard and applies a bleed. Let's not forget that lacerate procs a reset on your mangle cooldown, being able to tab mangle is very nice for threat
For trash the rotation at 80 will be Swipe/Maul -> keeping Lacerate rolling on as many targets as possible to mangle/tabmangle as many mobs as possible. Also remembering to thorns at the start is a good thing, in ICC today my thorns was proccing on our PP main tank for I kid you not, 10k.
I feel pulverize only has use as a once in the rotation sort of deal.
My ideal single target rotation will be in order of priority
1. Mangle
2. Maul
3. 3x stack of Lacerate
4. Swipe
5. Keeping Pulverize buff at 9% crit (consists of 1 pulverize every 15-20 seconds)
6. FFF
this may be a little bit off but pulverize is only for the extra 9% crit i feel, especially as we want lacerate ticking to proc extra mangles.