According to the Elitist Jerks website, Frost DPS in both 2H and Dual Wield spec are roughly equivalent.  The downside is that the specs do not lend any flexibility to the playstyle – every point is being used.

Talents

[Dual Wielding] | 3/31/2 (80) | 7/31/3 (85)

DPS in this spec is done in Frost Presence.  Obliterate will be where the lion’s share of damage is done, with Frost Strike and regular white damage following right behind.

[Two Hander] | 3/31/2 (80) | 7/31/3 (85)

DPS is done in Unholy Presence, with Frost Strike taking the lead as the primary source of damage, with Obliterate and auto attack following right behind it.

Glyphs

Prime

• [Glyph of Frost Strike]
• [Glyph of Howling Blast]
• [Glyph of Obliterate] | [Glyph of Icy Touch], for AoE.

Major

• [Individual’s Choice]
• [Individual’s Choice]
• [Individual’s Choice]

Minor

• [Glyph of Path of Frost]
• [Glyph of Blood Tap]
• [Glyph of Horn of Winter]

These apply to both 2H and DW specs.

Rotations

This is how the pros see it:

Single Target

Diseases > Ob if both Frost/Unholy pairs and/or both Death runes are up, or if KM is procced >
BS if both Blood Runes are up > FS if RP capped > Rime > Ob > BS > FS > HoW.

First thing first: as stated toward the beginning of this post, dual-wielding will perform this in Frost Presence while those using a two-hander will be best off using Unholy Presence. The reason for this difference is due almost entirely to MotFW; not only does the talent substantially increase the value of quicker attack speed, but it also GCD caps the spec by a moderate margin, which makes the 1 second globals of UP priceless.

Beyond that, everything is relatively straightforward:

Diseases come first, as always, with Frost Fever being applied by Howling Blast and Blood Plague being applied by Plague Strike. With Rime, you should never have to worry about FF… the odds of going without a Rime proc in a 33 second window are absurdly low. BP maintenance is simple enough – if you have an Unholy rune come up from an RE proc when diseases have about 6 seconds or less left, then go ahead and use it on PS, otherwise just use the next rune that regularly respawns, be it Unholy or Death. When doing so, you may be left with a Frost rune sitting by itself; it’s best to let it sit unless the other Frost rune is also up (or if you need to refresh FF), in which case merely HB.

After that, you prioritize Obliterate and Blood Strike if both runes of the relevant cost (UF/D or B) are up. The reason for this is the same as it’s always been – you don’t want to “waste” runes by sitting on them, when you could have them cooling down. On top of that, if KM is up, it’s always better to use it on Obliterate than on the alternative of Frost Strike. Ob simply hits harder.

Similarly, you want to FS if RP capped, as wasting runic is just as undesirable as wasting runes.

If Rime is up, then you obviously want to use it. There’s no need to worry about KM: Rime neither benefits from nor consumes the buff any longer. You never want to Obliterate back to back without having used a Rime procced by the first – and if you’re following this priority, that won’t occur, anyways, so not a worry.

If all of the above is taken care of – you have no more than one of each rune type up, KM isn’t active, you have less than capped RP, and Rime isn’t up – then you simply Obliterate and Blood Strike as you can. Remember, under the new rune system you can sit on runes so long as you don’t have both of a single type up, and you won’t lose any dps.

Following that, Frost Strike. Make sure you’re not Frost Striking when you don’t actually have all six rune on cooldown, as if you only have three, they’ll be recharging, and thus RE takes a hit. You need to have runes fully depleted for to make the most out of RE.

And, of course, when left with no other option… Horn of Winter.

Multiple Targets

The AoE rotation is actually quite different than the single target one:

HB if both Frost runes and/or both Death runes are up >
DnD/PS if both Unholy Runes are up > BS if both Blood Runes are up >
FS if RP capped > HB > BS > DnD/PS > FS > HoW.First off, Frost Presence is mandatory whenever adds are present, whether you be dual-wielding or using a two-hander. No exceptions.

There’s no need to specify applying diseases: you’ll constantly apply them with glyphed Howling Blast (which is your hardest hitting ability, of course) and PS (which you’re going to be tab “spamming” due to the fact that HB leaves you with leftover Unholy runes anyways). Using Pestilence just isn’t worth it when you consider all of that, on top of the whole 50% penalty going on – you might use it when you have a dozen adds up, but rare exceptions like that are it.. You’ll still prioritize DnD over PS whenever it’s off cooldown, of course, but that’s a given.

Following that, you still want to Blood Strike with your runes, not Blood Boil – the reason being BS converts to Death runes, while BB does not. Since a BS + HB > 2x BB, simple decision, although if you’re in a scenario where you won’t be AoEing for ~10 seconds (long enough for the Blood rune to come back up as a Death), then yes, BB does more immediate damage.

Then, of course, comes using runes on HB/BS/PS/DnD as appropriate, followed by the dumping of runic into Frost Strike for RE procs. Nothing fancy.

Stats

Pretty much what you’d expect:

Dual Wield
Hit to cap >= Expertise to cap > Strength > Mastery > Haste > Crit > Agility > Hit to spell cap

Two Hand
Hit to cap >= Expertise to cap > Haste > Mastery > Strength > Crit > Agility > Hit to spell cap

If you’re looking for more of an explanation of why things are set up the way they are, or looking for enchants and so on, you can get a fleshing out of this bare bones post over at Elitist Jerks