I guess the obvious replacement is Alpacapatrol? That would be pretty awesome, although I would really love to see BaerTaffy on the show. I think Kate is usually at work during NLSSes, apart from that I guess maybe Mathas?
edit: Maybe two new co-hosts? http://ask.fm/Northernlion/answer/115710056870
Gang Beasts. Ragdoll physics, fighting, silly art style, grabbing/pulling/throwing opponents/etc. A lot of fun for 2-4 people, looks like it was made for silly NLSS segment.