RAM is 512MB DDR3 and there is 2GB of NAND FLASH memory so there is no need of an external memory card with the Operating System which by default is Android 2.3 that comes pre-installed.
First impression out of the box and first boot, so far so good, I did connect it to my Samsung monitor via the VGA interface, small mouse and keyboard, hooked up to my lab network, powered it (power supply is included) and it took Android less than 10 seconds to boot.
There are not that many applications pre-installed, you can't install them directly from Google's play, but there is plenty of 3rd party sites with Android Apps that seem to work fine, more about it soon.
Take in account that this is a platform that is still under development and that this is the very first batch of boards made.
Didn't do much with the Web browser App included in the pre-installed image, but did try the YouTube App playing a trailer of Skyfall and it was flawless with great audio quality using earphones.
Here is a video of Rich Brown's talk at TED about the $49 PC.
More about it coming out of the lab soon ...