This time, I prepared myself. I got all my inspiration from Elitist Jerks' section on dual-wielding Death Knights. This was exactly what I needed: a good cookie-cutter build for post 3.2. I love cookie-cutter builds. In many cases they are not ideal for my case since I don't need skills that are very useful in a raid situation but useless if you go solo. The first DW build on Elitist Jerks' page is different in this respect because all the talents that are useful in a raid setting are also ideal for solo-ing.
Thus, my Dual-Wielding spec became the following:
I didn't just blindly pick that spec but I looked at each talent and tried to understand how it makes sense. I won't go into details but Elitist Jerks claim that this is "the most promising frost DW spec" currently and I believe them. It has a lot of goodness in it.
You will also notice the glyphs that I picked in my spec. Although they are recommended as "ideal" for this spec, I would have picked the same ones had I not seen that article. I just love specs which make glyph choices obvious.
In short, as far as the spec, glyphs, rotation, rune forging and weapon choices are concerned, I followed the exact advice on the Jerks page. It just works.
If you haven't seen my Blood Death Knight gear article, then you should know that I'm still wearing the same equipment. I have stopped investing in gear for my DK because he's good enough the way he is and he won't have any problems leveling up in the next expansion.
For Dual-Wielding I needed a pair of nice 1-handed weapons though. Currently, due to the new mechanics of DW, it is ideal to use the slowest weapons possible, in both hands. Speeds between 2.5 and 2.7 are what you should go for.
So I turned to the interwebz and started searching for the ideal pair. I found the only weapon that is easily available to a solo player: Reaper of Dark Souls which can be bought from the Knights of the Ebon Blade at Revered. Fortunately, I was already Exalted with the Ebon Blade so not only did I have easy access to this weapon but I also got it at a discount. Well, 2 of them in fact, because this weapon can be equipped in both hands.
I'm really happy about finding this weapon since it's a ilvl 200 item, the damage and stats on it are excellent and the speed is as slow as it gets, at 2.7. It seems that this weapon was meant for Dual-Wielding Death Knights. Or Combat Swords Rogues.
I won't go inti detail regarding the rotation. You can find the details on the Elitist Jerks page.
Essentially it's: apply diseases > Obliterate > RP dump. If Rime or Killing Machine proc, these take priority. Ideally, you should wait until they both proc and you will have a free Howling Blast that also crits.
The Good about this spec is that to me it seems as good - if not better - as my Blood spec. It certainly feels more fun. I like using 2 weapons more than a slow 2-hander. Now I truly feel like a rogue in plate.
The Bad is that at least in my case, mobs go down so fast that I don't have time to run through the ideal rotation.
The Ugly. Well, there's no ugly for me but there's plenty for the mobs I encounter. Very often I crit for over 4K and that's on par with the damage from 1H Blood. Wow! Another awesome perk from this spec is the abundance of Runic Power. RP is generated quickly and very often I'm barely halfway through my rotation and I fill up 130/13o RP. Thanks to this, I will throw in Rune Strike in my rotation without any hesitation, because it's on a separate cooldown. I'm even considering using Death Coil to pull mobs when I have excess RP. Yeah, I know that's not really part of the spec but what the hell.
Post 3.2 Dual-Wield Frost is once again viable, fun, very powerful and similar in rotation to Blood. Try it if you haven't. There are high chances that you won't turn back to your old spec.