Is there anywhere I can find listed CM9 or planned CM10 features? I've been ROM hopping like crazy and I'd just like some concrete features to compare. Also in Settings>Wireless & Networks>More>Tethering & portable hotspot...is that tethering through VZW or through the ROM?
Well it uses VZW network, but it's a feature of being rooted/rom/generally.
For features, check out the CM website. Generally, there are status bar modifications, power widgets (notification drawer toggles), navigation bar mods (the soft keys), and a whole slew of other things (profiles, power menu stuff, etc. etc.).