Mabye fix rally to give a HoT to your team... >.<

Gimme a reason to use it for a SS, leave the HoT off support champs and put it on rally.

It used to do this - it was removed

Taric used to have a team HoT, which was ridiculously OP.

Only productive outcome of this thread!

what exaclty "healing over time" means to yo?

Have you ever played garen, mundo?

A heal over time is like that Ronco rotissere cooker. Set it and forget it. A normal heal needs to be timed so you don't over heal and maximize costs and cooldowns - a heal over time you just cast on someone who you know will be targeted or is getting targeted and you don't have to worry so much about overhealing or wasting mana or cooldown because as long as it's going it's being effective. At base levels they are the same, but add in cooldown reduction, mana regen and large amounts of ap and a HoT becomes much better than a direct heal.
Here are some situations:
You have a high priority target, or HPT, on your team like Yi, MF, etc. and you want to start a team fight. With a direct heal (DH) it becomes most effective when your HPT has taken exactly the same amount of damage as you ability heals for, so casting it before then is not an optimal choice. Now if you have a heal over time (HoT) you can cast it as soon as your HPT has lost as much life as the first tick. To add some numbers, lets say they both heal for 400 health, with the HoT being over 4 seconds.
DH is optimal at a deficit of 400 hp, whereas the HoT is optimal at a deficit of 100 hp. You may be wondering "well what about the other 300 hp the HoT would heal for but becomes overheal if they switch targets?" which is valid, but not in as many cases. Most of the time, people focus a HPT regardless of healing hoping to burst through the healing so a HoT is just more efficient at dampening the damage because it is optimal sooner in a fight.

Another one is in close fights, HoT's are more deceptive than DH's. Lets say you are in a 2vs2 encounter where it is very close, with a DH seeing a large burst of hp returned to your target may make you want to retreat seeing as how they have more durability left than your side does. With a HoT it is not as apparent, especially with longer duration HoT's. Lets take Soraka's old HoT, which lasted 9 seconds, lets say it also ticks for 25 per second. Now if you have a target at 200 hp, and she casts her heal, over 9 seconds they will have an extra 225 hp, which is not as noticeable as 225 in 1 second for a DH. Having that longer duration might make most people think "they are so low, I can finish them" but if you cannot out damage the rate of the heal plus their starting 200hp over that 9 seconds then they live and you have stuck around in a potentially bad situation longer than you wanted, 9 seconds for the HoT vs 1 second for the DH.

In situations where a target is at a deficit of more than the hp of a DH or a total of HoT then they are equal in power, but the HoT is more deceptive. When targets are at no deficit a HoT becomes optimal sooner - as well as allows for easy pre-healing. Pre-healing allows a healer to set a HoT and then have the rest of the duration to do other things, only worrying about re-healing when the cooldown comes back off - and with CDR sometimes they overlap, so it becomes less stressful than a DH.

No HoT's are not more powerful or less powerful than equal value DH's, but they add a psychological effect against your enemy that is not fun to deal with and eases the level of difficulty for the healer.

On a side note, think of how much more annoying it is to deal with a HP regening tank like Singed or Mundo or Mordekaiser (counting his regening shield) - they can stay at a sliver of HP for what seems like forever and not die. Dealing with tanks that are not regenerating as much, like Shen, Rammus and others becomes less stressful, you can see how your rate of damage is effecting their decline in health easily. Again, regeneration tanks are not necissarily better than the other tanks, they just have that psychological edge as well as ease of use.

Taking the two worst offenders of regeneration - Mundo and Singed - if they build armor and magic resist with hp, getting them down can be a pain - but then they activate their ultimates and their regeneration skyrockets and they may even outheal your damage, turning the tides very quickly. Playing Mundo a lot, if my ultimate is off cooldown, I essentially have 70% (rank 3) of my max hp extra, so I may look like I have 3k max hp, but I really have 5100. Seeing a tank that has only 3k hp is less scary than one with 5100.

Anyway, /end rambling.

And yes, short cooldown direct heals are essentially heals over time when spammed. Sona is really bad about this because of how high in power her heals are vs their extremely low cooldowns. Her heal is basically a heal over time with unlimited duration as long as she has mana because it requires no targeting and thought of which target to cast or when.

To be honest if I could port 1 class from WoW...I'd rather see a Warlock. That had all Dot's, maybe one nuke that were not respectively strong but you could keep them up on rotation. Say the ultimate would be the different curses. I'd like that.