The site says that they are coming February 2011. Well, it's February! I am impatiently waiting to find out how much they will be charging for hosted stores. I'd host my own store except that I take credit cards and use Propay. There aren't many hosted carts that allow sellers to use Propay. It's an eBay company, and even the eBay ProStores don't work with it. I'm thinking Magento Go won't either, but it would be worth getting a merchant account and all if the monthly rates for the Magento are low enough.
Turned out the monthly rates are pretty high, actually. Yet still not high enough to get some support. See this thread for the reviews: http://forums.digitalpoint.com/showthread.php?t=2244078#post16845560 It's simply amazing to see how they can be so UNPROFESSIONAL.