Originally Posted by boourns
The key point of debate in that situation is whether you want to look away from the fight for that information. This totally makes sense if you're in vent or skype and your AD is telling you to let them get the kill because they have ignite, etc. However if you're in the middle of a fight, are you actually going to want to look away from the action to see if one person's summoner spell is up? We currently think it would be very challenging to present this information in a way that is useful to players in a stressful gameplay situation. So more investigation of creative solutions is necessary!
tldr: Knowing this information is clearly positive for gameplay, it's unclear whether the sidebar can convey it well in team fights.
No offense, but that argument is kinda silly to me for one simple reason:
High ranked players already do look over to see what team mates have their ults up. With this we can tell if our support has their heal, if our carries has their ignites, and if anyone can clarity in case the fight takes a while. While newer players may not find all this information as useful, I'm sure lots of people in solo ranked queue would love to know if they should try to wait that extra 7 seconds for that last person's ignite to be up.
Edit: In fact, people also look over there all the time to see how low their team mates are on health and mana. Playing as Shen top he could possibly save his ult knowing that an ally has his flash up, or save one ally who doesn't have flash up and leave the one that does have it alone.