I raid as an arcane gnome mag and honestly i never go oom i dont even need to use pots i have over 12k mana unbuffed. gnomes have a clear advantage in specing arcane buff to the racial but arcane can be as good as a fire mage if not better in dps frost is hard to use in tk ssc hyjal freezing things does affect ur cc and u have to get within ur max range to do it. Arcane has many raid advantages 40% threat reductioin is invaluable i dont even think about my threat anymore 10% hit rating allows u amazing flexability with ur gear and gems as only 76 hit rating is needed to be at the cap which is the most important thing to dps. this allows you to stack more spell damage and int. A simple raid rotation is ab ab arcane missles then follow up with a ab timing it to the debuff. Simple as arcane i out dps everyone as long as im not on sheep duty. but yes 40% threat and 10% hit make arcane superior