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

[Ramsey]

There's nothing inherently wrong with moving and casting, the ability to move and cast time of a spell are just factors in balancing a spell's effectiveness.

The problem is FFXIV has no instant cast spells, which can be used while moving. Most MMO casters have a mix of instant cast and channeled spells. Honestly I have a hard time wrapping my head around the whole thing being a PvP balance issue. I remember before the patch that your character still stopped moving to start casting and to fire the spell, which would surely slow you down more than enough for a melee class to catch up. You also can't run jump/pivot shoot/pivot and continue running in FFXIV due to the control scheme.

Hopefully in 2.0 there are a mix of move-while-casting, stand-still-to-cast, and instant cast spells.

Moreover, if they simply asserted that your character stop moving whenever you input a spell cast with a cast bar, and then did not take any movement input until your stick re-centered (or you let go of the movement keys) they could effectively eliminate all the accidental/lag interrupts. Loss of visual quality shouldn't be a concern, there are plenty of ways with blending and queuing to make it not abrupt.

[Rowyne]

The problem is FFXIV has no instant cast spells, which can be used while moving. Most MMO casters have a mix of instant cast and channeled spells.

Exactly. Healers generally get an instant-cast HoT (heal-over-time) they can fire off while moving that helps keep people topped off in between fights when your group is on the move. It's not as powerful as a channeled cure, but it's not meant to be. I think that alone would alleviate a lot of the annoyance healers are feeling right now.