It’s been said many times that Blizzard is comfortable with Frost being the dual wielding tree for Death Knights from now on, to give a different flavor to the tree and to distinguish it from the other 2 trees. But we know that is wasn’t always that way as evidenced by the many Frost specced tanks back in the day wielding two-handed weapons.
Eventually dual wielding became more and more accepted for Frost and then Blizzard added the Threat of Thassarian talent to really support it. The small problem with dual wielding one handed weapons was that it never had any strength on them, a stat that was most desirable for Death Knights. Some of them had just attack power while some had agility and attack power but never strength. Basically they were making use of weapons that were intended more for hunters or even rogues.
This is going to change in the Cataclysm expansion, according to Ghostcrawler. Finally Blizzard is going to make dps one handers with Strength on them to fill this need for Death Knights. This is especially important because of the stats changes in the expansion. Right now Death Knights are making do because of the attack power on these weapons but that’s going down the drain in the expansion. Since Death Knights, along with Warriors and Paladins, will get their attack power from Strength this is really needed.
This brings me to another related issue. It seems to me that when the new stats system gets rolled in, these current dual wielding Death Knights could be screwed until they get new weapons with Strength on them. Logic suggests that with the new stats system, these weapons could be useless to Death Knights. The attack power that Death Knights want from these weapons will be gone and since they’re really hunter weapons, that attack power could turn into Agility instead of Strength. Unless they some flat attack power on these weapons just like they’re keeping some flat spell power on caster weapons, there’s really going to be a problem.