One of the biggest problems with group content as always been, people standing in the bad. The pressure to try to be competitive in the Dps charts sometimes means that our damage dealing companions, especially those with long casting times, often linger longer than they should in the bad stuff.
There was once a simple rule in WoW, "Do not stand in anything on the floor". This was nice and easy, a boss would light up the ground around you and you would move providing you were not too engrossed in your spell rotation to notice.
I notice a change around Cataclysm when doing a Lost City of Tol'vir. The entrance has spellcasters casting Earthquake and the whole place was shoot and run. The interesting change that occurred was that Shaman healers had now got some new spells in their arsenal including a ground AoE healing spell with a large Blue circle on the floor. The result was that everybody immediately ran out of the area to avoid the horrible effects of this blue spell.
The spell we now know is Healing Rain and it was part of a design normalisation process that Blizzard introduced for the new Triage healing system. The idea was that Healing classes would have an AoE healing spell, a quick heal, a medium low mana heal, and a big heal for big mana.
The problem with the ground effect spells, is that there are way too many of them now. We have Offensive spells like Earthquake and Death and Decay, and Healing spells like Healing Rain and Efflorescence (Circle of Healing - maybe). The result is Green, Blue, White and Red circles on the floor, and that is just the crap that your allies put on the floor. Add in the boss spells and it make for one gigantic mess on the floor. God help you if you suffer from colour blindness.
The one saving grace in this pile of confusion is addons (don't rely on Blizzard to save your sorry ass). Deadly Boss Mods or Big Wigs should be installed as default for any endgame player. There is however one other useful addon that does only this one task, and I found it solely because I liked its name GTFO. The description on Curse is as follows:
Stop standing in fire!GTFO provides an audible alert when you're standing in something you're not supposed to be standing in. In some cases, you'll be warned before you start taking damage. This mod improves your situational awareness and is recommended for dungeon divers and raiders of all skill levels as even the most seasoned veteran sometimes needs a reminder to GTFO.
It's particularly useful for individuals that play with their spell graphics turned down as well as assisting with PvP when you can't tell who's casting the AOE.
Audible alert, is my first problem, I tend to play when the children are asleep, and there is no way I am playing with headphones on for hours at a time, just to drive myself insane with all the pew pew noises.
From the GTFO description it talks about the issue of spells being turned down, and this issue applies equally to people with older computers with bad graphics cards. If you have a rubbish computer you need an addon and the sound turned on, or you have a decent computer with an addon and sound is optional.
The whole situation is a little on the muddy side and if Blizzard want us all to Raid or at the very least LFR then they should really be looking to clear up the effects or at the very least be incorporating their own raiding addon. So much of this game is player led and the game is so vast and complex that we need to do research to be able to play some of the basics like grouping. It might be second nature to the raiders amongst us but for the new players in an unfriendly environment like LFR, this must be absolute chaos.