Balance Druids are another spec getting a pretty significant redesign. The Balance Meter was always a bit tricky, but it became just kind of bad in Warlords, moving solely based on time spent in combat. Druids' ranged dps spec is getting rebuilt, and much like DPS shamans, they're getting a new resource that replaces mana (and they're losing the Balance meter.)
This new resource is Astral Power. Balance spells are actually cleverly broken down into three categories - Lunar, Solar, and Astral. In general terms, Lunar and Solar spells will build up Astral Power while Astral spells will spend it. Many of the spells kept their old names, except a few that were adjusted to fit the theme better.
Solar Wrath is basically just Wrath, and now generates 9 Astral Power.
Lunar Strike is kind of the new Starfire, dealing Arcane damage and generating 12 Astral Power, as well as doing splash damage to enemies near the target.
Starsurge then costs 40 AP, dealing Astral damage (they're really coming up with a lot of new damage types, unless this is just a new name for Spellstorm, which was just a combination of Nature and Arcane.) It also empowers your next Solar Wrath AND your next Lunar Strike, with both buffs stacking up to three times - there's your motivation to use both spells.
Sunfire is largely the same, as is Moonfire, except that with no Balance Meter, these are now separate buttons, which is actually probably going to make it a lot easier to maintain them. Sunfire still hits multiple targets and Moonfire lasts longer. While not huge for Balance, Moonfire can now be cast in Bear form.
Starfall now targets a location - kind of like an instant-cast Hurricane (which I believe is gone.) It costs 60 Astral Power and increases the damage of your Moonfire and Sunfire on any targets in its area by 30% - so you'll still want to multi-dot, but you can toss this in as part of your AoE rotation.
Celestial Alignment is your big 3-min cooldown, increasing all Solar and Lunar damage by 30% and also giving your Solar Wrath and Lunar Strike 50% additional AP generation.
So, before talents and artifact traits, the single-target rotation seems rather straightforward:
1. Maintain Moonfire and Sunfire
2. Cast Starsurge, unless you're capped on its buffs. Though maybe if you're in danger of capping AP, you'll be willing to waste the buffs.
3. Cast Solar Wrath and Lunar Strike if you have the buffs.
In AoE, I think you'll probably just cast Lunar Strike to generate AP (since it does splash damage) and then multi-dot it up and cast Starfall whenever you can.