RPi 1 to RPi 2 with same SDCard

[namtih]

I assume that you're using just an SDCard and no USB installation. Create a backup of it first with this little app:
http://sourceforge.net/projects/win32diskimager/

Boot your system and close Kodi.
Then update the firmware:

Terminal

sync
sync
sudo wget -O /boot/fixup.dat https://github.com/Hexxeh/rpi-firmware/blob/master/fixup_x.dat?raw=true --no-check-certificate
sync
sudo wget -O /boot/start.elf https://github.com/Hexxeh/rpi-firmware/blob/master/start_x.elf?raw=true --no-check-certificate
sync
sync

Then check your "config.txt" and remove all overclock settings.
Then shutdown your system and give it a try in the Rpi2. If it's not booting, boot your Rpi1 again and try a full upgrade via the xbian-config tool. Then try it again.

If you have no luck, restore your backup image created at the beginning with the same tool.
It's all not tested as I personally started with an complete new installation - so it's your own risk. It's just an idea what I would try.
Good luck.