At first glance the news seemed cut and dry, but then the mystery came upon me. See, 2nn's post features a teeny-tiny image that could very well be such an announcement-- it definitely says Lupin III VS Detective Conan –but because the image is so small, it's hard to tell the exact context; it could just be a magazine feature that has them both, rather than an actual new anime announcement.
The reason for my skepticism is that the 2ch thread that 2nn linked to has a source link whcih probably originally went to the above image, but has now timed out; the link now just forwards to a porn site. (Don't say I didn't warn you.)
So let's hear it, gumshoes: do you think there's really a Lupin vs Conan special in the works? And seriously, how awesome would that be? I'd totally watch it. On the other hand, it's not like hoaxes haven't made it through 2nn's filterers before, and I haven't been able to find any other confirmation at this point.