Toying around with a mage in battlegrounds, decided not to go ice cause thats a lot of work, so I went fire spec instead. In terms of stats I went for a mix of survivability and mana. I did the same thing with my level 60 lock back in the day. A good bit of stam can go a long way with the hit and run afflict locks and scorch spec fire mages. Sure if youre some RAID mage you can sit and fire nukes, but when yer in BG you have to be prepared to get your hands dirty!
Here's my current 39 spec. (Im 38 but im just adding another point to Fire Power)
http://www.worldofwarcraft.com/info/classes/mage/talents.html?0000000000000000000000005223201230203122000000000000000000000000000Impact - SO useful to add stun chance when tossing out the fast fire spells (scorch/fireblast). Also useful when using Flamestrike/BlastWave
Flame Throwing - Added distance is essential.
Improved Fire Blast - By 39 your fireblasts will crit for close to 500 if you do it right, and having a quick cool down on an instant cast that powerful is important.
Ignite - Still not sure I want this one, the dot is nice and keeps rogues from doing their vanishing shit tho.
Burning Soul - Avoid those embarassing spell interrupts.
Incinerate - +4% chance to crit scorch or fireblast. My natural crit chance for fire spells at 38 is 14.7+%, add another 4% and OMG, 1.5 sec cast scorches can crit for upwards of 250, and may stun thanks to impact wooo. Plus fireblast crits = ftw.
Pyroblast - USELESS for PVP, but a stepping stone to something important, BLAST WAVE
Master of Elements - Scorch is a cheap spell, but Fireblast and BlastWave are not. Keep yourself going with some mana refunds! Not sure ill max this one out yet.
Blast Wave - Crowd control for those too close for comfort moments. This thing hits anyone in range, potential to daze and its crits are close to fireblast level. This spell also flows well into the use of other spells for some extreme damage.
Critical Mass - This is what gets my natural fire spell crit chance to almost 15%.
Blazing Speed - 10% chance to enter +50% speed for 8 seconds and escape immobilizing effects on ranged or melee strike? Essential for flag runners or mages who love to be in the thick of it. Ultra annoying talent for people trying to finish you off.
Firepower - The name says it all. IM DEMAN MOAR!
Improved Scorch - Added fire weakness, stacks up to 5 times.