Supernova and Supreme? Basically another world.
Supernova = Sense, Supreme = AOSP
Supernova = RAM heavy, Supreme = extremely light
Supernova = Expects Data2SD, Supreme = can work with any A2SD script (yes, Data2SD too)
Supernova = doesn't support special tweaks such as WiiMote Controllers, Supreme = AOSP, so it does
Supernova = meant to be ready for immediate use, Supreme = contains a lot of optional tweaks
Supernova = no USBH support (not even a HOST kernel), Supreme = can give a link for USB Host Support (with kernel downloader)
Supernova = Sense, so not really skinnable, Supreme = CM7 based, skinned by default, with a lot of optional skins from the Android Market
No disrespect to Supernova btw, it's a great ROM!