As it stands now, the OS will support up to 1GB of RAM for applications. Given multitasking of third party apps isn't supported, this should be plenty. 2D graphics and Direct3D 11 runtime libraries will be supplied by Microsoft, but device manufacturers will develop the drivers for graphics. I almost wish MS would develop the drivers as well. There were some instances with previous versions of Windows Mobile where a killer video chip would be in the device and then a lame driver would be written that wouldn't exploit the chip to its fullest
Bluetooth 2.1 is supported, but 3.0 and 4.0 aren't. I don't know too many people that know what the higher revs of the Bluetooth spec have to offer and even fewer screaming for that support.
Details on memory cards are a bit shocking. It appears that the OS will treat files on internal flash ROM and memory cards as a single location. This would have been a huge benefit in WinMo 6.x, but in 7 where the file system isn't really exposed to the user, I don't know how much difference that makes. Here is the shocking part. If the document is accurate, should a memory card with key files be removed, get erased or malfunction, the phone will be rendered virtually useless. Emergency calls will be allowed, but not much else. I would think a hard reset to factory defaults would restore full functionality, sans all of your apps and data.
The report has plenty of other juicy details about the OS if you are interested. Hopefully in a few months we'll start seeing leaks on actual devices.