They hit 60 in the sprint events. You could argue that it should be similar. Speed skaters and cyclists use about the same muscles and have similar front cross-section. That leaves the difference of rolling resistance vs steel on ice, but both, IIRC, are low compared to air resistance.
Speed skating speed drops off faster at longer distances than cycling, though. I think that’s mostly because you can’t for any moment rest while staying in the ideal low body position. They also run out of oxygen faster because sitting low to lower air resistance isn’t ideal for breathing.
They're not running out of oxygen. The real limiting factors are glycogen depletion and build up of waste products from anaerobic metabolism. On longer races cyclists can consume extra carbohydrates which helps a lot.
Yup. The men's world record 10k is the 12:30.74 in the link. I think the longer blades on the skates help reduce overall friction, and modern skates have this detach function in the heel which lets the whole blade stay on the I've for longer, both of which help speed.