Napalm's been representing viking/folk metal for quite some time now, Kampfar, Korpiklaani (formerly), Vintersorg, Tyr, Asmegin and many others. I'm pretty sure they've been signing bands like this before it got extremely popular, but I'm no expert on their band roster timeline.
Anyways, I'm very glad about this news! Arkona is a band that I really enjoy and I'm glad that they will be getting stronger representation and distrobution.
Well the second handers have clung to about every sub genre of metal under the sun, aside from doom. Once they're done infesting the scene with every last hybrid shit blend they can mathematically come up with, expect a punk rock revival.