I read through the development blog. Mummies are called Arisen. They were created in pre-history in the most powerful magic ever worked by mortals. Their spirit is forever bound to their physical body.
The big theme is Memory. People weren't designed to live for 6,000 years. It looks like Memory will be like Humanity for Vampires.
Mummies can do magic, of course. It's not like magic is Mage, or even really in Vampire or other games. It requires specific rituals, and also the spell is etched into your being. The spells are more like explicit acts of God than the subtle magic of the other PC races. Magic is powered by magical energy that accumulates in historical objects.
One cool component is lesser magic that you learn on the fly. It looks like it's still specific "spells" but you can buy them during play. And once bought you have them forever.
The game has five pillars related to the five core ancient Egyptian components to a person: heart, spirit, name, essence, and shadow. These pillars will be worked into the system in a way that doesn't mirror a pre-existing game, which to me sounds cool (but I always like the really old oWoD mummies that were their own system).
Each Mummy has a Decree, which is like a Clan or Tribe. It associates them with one of the five pillars.
PCs start out more powerful. You arise from the dead at the height of your power, and you can start with a cult to do your bidding.
There's a separate GM's book that has details on the setting's history the players aren't supposed to read. Part of the game is learning more about that past and in the process gaining power (I think).
Mummies organize themselves into Guilds to teach each other magic and other Mummy stuff.
That's everything I got out of the blog. To be honest, it sounds cool and I think I want to run it.