Some new screenshots should be appearing in the next "Ambrosia Times," as far as I know.
To address some concerns I've heard:
You will be able to import sprites into Hera. Using your own graphics programs, you'll create a graphic file that has each frame of a sprite laid out on an invisible grid. Hera will be able to read that graphic file and translate it into the Ares sprite format.
You will be able to create network scenarios.
Hera will require a PowerPC and at least an 800x600 pixel display.