Could you please give more details on following questions:
Will CuBox have any OS already installed just out of the box?
The platform will ship with Ubuntu distro by default. As interest goes more and more we will see more distros ported.
The reflashing mechanism for installing new distro, or dedicated application is easy, and will be done via USB stick.
Are there any recommended Linux distributions for CuBox or we can use any one?
Typically a distro that supports ARMv7 and VFPv3-d16 instruction sets would be best, in order to get best performance.
Best if using hardvfp, but currently we haven't ported any (Debian probably will be first).
Can CuBox be booted from bootable linux USB-flash drive?
Yes. We will write a wiki page about the boot process, but every system shipped tries booting from all peripherals by the following order - micro-SD, USB drives, eSata and gigabit Ethernet via TFTP and then NFS or other methods.
We might swap micro-SD and USB drives order so that the system will try to first install from USB and then boot regularly. Your thoughts will be helpful here.
What kind of steps have to be performed to install new OS on CuBox?
We invested a lot of though about this since we know people like changing distros and firmware alot.
The current process is by simply downloading images to a USB stick and then rebooting system, it will auto-install to the micro-SD that ships with the box.
Other thoughts were aroused like providing a GUI with the box that the user selects and automatically gets downloaded, or even using torrents to auto-install, but none of those were implemented, yet