Once the bootloader on your embedded device is up and running the development of kernel and userland in PTXdist-based BSPs is usually based on booting from network. Thus there is no need for the developer to write the boot media with a new image.
At Pengutronix, one of the most important tasks in our industrial linux projects is testing of embedded systems. While testing is easy on the component level (there are many unit test frameworks around), it is increasingly difficult on system level. Tests do not only run code and compare results, they need to bring the device-under-test into different states (i.e. "bootloader", "linux console", "power off"). If you have many embedded Linux devices, remote-controlling power, serial consoles, network, switches, reset lines, SD cards in scalable, automatic labs is also on the wishlist.
In the first talk today, Michael Tretter reports about the current state of Open Source Graphics for Embedded Systems. For regular observers, it's probably not surprising that the focus will be on i.MX6, Etnaviv and the IPU.