Moving will be made to interrupt spellcasting at a point in time...

[Orophin]

All I have to say is DON'T make balance decisions for PvP that negatively affect PvE. That was a big reason I got turned off WoW.

[Monsalvato]

All I have to say is DON'T make balance decisions for PvP that negatively affect PvE. That was a big reason I got turned off WoW.

I concur.
Blizzard always refused to balance things in two different ways (i.e. making so they work in different ways in PvE and PvP) for two reasons:
1) too much work
2) ideological "defeat" of their approach

But that's what ultimately caused a lot of balance issues and, in the end, they probably had to put in much more work than they would have if they went for the "dual" approach from the beginning.
Dual approach is just the best in these situations. It allows you to make so that abilities that would normally be useful only in PVE (like Provoke) can have an use in PvP as well, by working differently on other players than they do on monsters.
This fine-tuning that changes how your actions work (altough it should normally be small changes/rebalancements of course) surely requires much more work at start, but in the long run makes everything more balanced and players happier.
Those who like PvP won't have to see some of their things dumbed down because of PvE issues and vice-versa, etc etc etc.

I completely support this!