Good news to all you Dual Wield Death Knight Diehards: Ghostcrawler recently popped up on the forums with a simple answer to your woes: "Next Major Patch."
Apparently, the next major patch (I'm guess it will be patch 3.2) will be seeing more tweaks to Death Knights, at the least to get dual wielding viable again. There's no word on what form this tweaking will take, which is to be expected. Balancing Dual Wielding and Two handed weapons has always been a tricky to near-impossible for other classes, so the skeptical part of me still wonders if it's possible.
Of course, it could also be the two-handed weapon partisan in me speaking as well. Any basic solution such as creating a two-weapon strike seems like it could leave two-handed Death Knights out in the cold, at least for DPS. Still, we have that earlier mention of possible dual-wield dedicated tree, so who knows how extensively they'll revamp whichever one they choose to allow dual wield optimization. We do already have some 3.2 feature announcements, though, so who knows, maybe class change information is up next. We'll keep you posted.