From what I can tell, this is new. It has a lot of the apps that many of the second-tier markets (i.e. SlideMe, etc.) don't have. It appears to be a client front-end for the brothersoft.com/mobile website.
I found Angry Birds, Swype, Nook, Skyfire, and a lot of other stuff that's harder to locate without having access to the Android Market, so hopefully it can help those with GT78s and other tabs without Marketplace.
Download it here. You'll have to choose a device to be able to download. I set it for HTC Hero, and that seemed to work fine.