Actually...if you take a look, it says it can be equipped in either primary or secondary. Therefore, if this is true, you could weild both and look like a ranger :) and if both effects stacked that would be some great dmg.
I doubt this can be equipped in either melee. It says that but so do some pal/sk 1-handers (I.E. Sword of Morning.) Hell, if I could use that in secondary along with my Frostwrath in primary I'd be dealing some nice melee dmg.