Yep, I was also worried that the clocks would be lowered. Doesn't seem to be the case. Then again, we don't know what position in the lineup these "8750H" will take (since Intel has completely changed the naming again). The scores (especially single-core) are not that different from the current flagship 7920HQ, so if that Coffee Lake is a higher-end model, the gain is rather moderate. Also, keep in mind that its Geekbench... so the only thing one measures here is a burst workflow under rather ideal conditions. The real-world performance could be different.
I expect good gains though simply because the energy usage of individual cores seems to be optimised and multi-boost is higher. You don't really get full single-core boost on modern CPUs anyways, since its extremely rare for the system to run on a single core (there is always something happening in the background). Its like Haswell vs. Skylake: in Geekbench its the same, but in real-world numeric computation Skylake is significantly faster.
Seems like it. But again, since Intel has changed their nomenclature, we can't really say for sure. We could even see the Xeon chips though since it seems that Coffe Lake mobile range includes some new mobile Xeons.