I currently have the STK1000 and love the fact that it boots and runs Linux from the SD card. It's been great for development and safe from the point of view that the SD card can easily be formatted and new software loaded using a PC without running the risk of doing something stupid and ending up needing a JTAG ICE to fix the problem.
I've had a look around and have not been able to determine whether UBoot on the NGW is able to boot a Linux kernel from a SD card as apposed to using the onboard FLASH. It would be my preferred method of development until I was completely happy with my software and configuration. Is it possible as the NGW would probably be better for my development than the STK1000?