http://us.battle.net/wow/en/forum/topic/7415601502~30% less damage than before without fireblast glyph, still 50% less when exploded with fireblast. The duration of the debuff was reduced to 4 seconds.
Frostbomb has just been hotfixed, again. Thats twice in 3 days.
GG Blizz, keep it up.