With the coming changes, I see no need to update any tank rotations. DK threat is fine currently, and having IT cause more threat will just make the initial second of a single target pull yield slightly more threat.
DK's AE starting threat is much more a problem than single target
for now ,i always delay my PS to get a DS/OB after the IT/HB(with GoHB) at 20 yards , don't need to do that with the IT buff at 3.3.3
after your 1st RS , your threat is fine, but with the IT buff , frost can easily droping BA for IIT to buff the raid that's another story
for blood , i don't see a need of IT spam for more TPS but lower DPS , and yes , blood still suck at starting AE threat , and i will stay at frost