not really now. at least there is no 'very simple' documented method to do it. there are instructions in the release to rebuild and deploy your custom kernel that explains how to do it with fastboot.
honestly, it is possible to compile on your PC (or even on the board), create a .deb file, copy it over to the board, install the .deb in the rootfs, generate the boot.img and flash it into eMMC, directly from the board, but it is not documented.. and you might be on your own..
one thing we would like to do in the long term is to have the bootloader pick the image from the rootfs directly (like uboot does), in which case we could easily upgrade/modify kernel for next boot, but this is not implemented.