Yeah, I'm sure there's been a bajillion threads on this already, but I've had this little idea for how Lightwell could be made into a non-useless spell.
Essentially, it's just like the enemy Priest's Lightwell in Trial of the Champion.Lightwell
Summons a Lightwell on the targeted area for 30 sec. Heals nearby allies(15 yards sounds fair) for 1952 to 2508*. Once you have been healed by Lightwell, you may not receive another Lightwell heal for 10 seconds. Lightwell may only heal every 0.5 seconds.
2 sec cast time. 2 min CD. 1200 Mana.
*This is the same amount as Binding Heal.
The 10 second cooldown prevents you from doing something like putting it next to a tank and having it just heal them over and over. Or from abusing it in Arena in the same way. It also ensures that 10 different people get healed.
It could also be like a shorter-CD "OH SHIT!" button, seeing as the only "OH SHIT!" button Priest has is Divine Hymn, on a massive 8min CD.