I don't know. If Nogi got defeated in the next ep by the triple rider, it'd be a huge letdown, and they'll have to introduce another villain for all the non-Kabuto riders again. I think he'll absorb the rider kicks and hit back instead. I predict Nogi will be Gatack's to defeat...he better live up to the name of god of battle.
Dark Kabuto is badass in his own way. I don't think they'll ever have a Dark Kabuto vs Nogi fight so we'll never know who's stronger. But guessing from the info from the scans, I don't think Dark Kabuto will have a Hyper Form. Rather, he will draw power from the environments Kabuto/Dark Kabuto will be teleported to, like fire, a meteor (GSL parallel, anyone?), and such. Plus it seems Kabuto will only go Hyper against Dark Kabuto in the final of the 3 fights.
Still, are they going to bother to explain Dark Kabuto's origins? Or, the worms, for that matter? Or Native worms? or the Masked Rider System? Or Zect? I have a feeling I WILL be disappointed, plot-resolution-wise.