It has blurred, and people do need to be more open-minded, but there are still clear differences in some cases. This is certainly one of those cases. Dropping in the region of 120 spell power for some pathetic amount of regen is NOT the right choice. If someone needs more regen, they should simply get gear near-equal to the best gear they can get but simply itemized with more intellect/spirit, rather than sacrificing a huge amount of damage for a tiny amoutn of regen and taking away the best regen trinket in the game from a priest or druid healer.
Yes I absolutely agree, but it seems more beneficial to gear up mages that do 1k more dps.
I wonder if it's started already - while the guys I play with don't give a rats ass we have had an app in the weekend from a s/preist who was told by his guild they probably won't be using him as shadow. Too many issues compared to how easymode it is getting another mage.