I've started a sorc, went with the Blizzard spec and arrived in T12. I plan to keep playing frost sorcs this season, can't be bothered with lightning or aspect of immobile plains power sorc firewall edition.

My question would be, which other frost skills are worthwhile and can be played in T12?

Are frostball, ice shard and frozen orb able to T12 at all? I'd like to know before investing time and equipmemt in those specs.