Phasing hasn't really seemed like that big of a deal in Cataclysm.
Sure there were points where the toons broke follow.

Same deal/fix as before.
Jamba gives notification that follow fails.
Push the key for slaves move forward, but not the active toon.
Once they're all across, press Follow.
And continue the journey.

I've not done a lot of PvE content so might be missing some annoying phase lines.

In WotLK, most of those were in Icecrown.
But they only interfered with maybe three of the eighteen or twenty dailies in my daily route.
Most of my toons live in Stormwind or next the the summoning stone for Vortex Pinnacle (Uldum).
Have not found phase lines to be an issue really.