It has everything to do with internet failures in general and that may cause latency too...
I'd say they do need to change Sejauni, since changing mana costs only buffed Skarner back then a lot
Sadly they won't touch balance for a while
---------- Post added 2012-10-10 at 11:10 PM ----------
Sejuani is not that weak, actually assume full items she is better than Amumu, with Randuin / Banshee / Warmog / Sunfire her W dmg will be insane and 2 W can take out most enemy team and you have resilience to survive that long (assume your team is not AFK), however the problem is to get that in first place