no.. you can't use windows 8 with bootcamp yet. According to the FAQ on bootcamp 4.0 you can only use windows 7. windows xp or vista (or windows 8) is not supported.
You can use Microsoft Windows 7 Home Premium, Microsoft Windows 7 Professional, or Microsoft Windows 7 Ultimate with Boot Camp 4.0. Windows XP and Windows Vista are not supported with Boot Camp 4.0.
heres the bootcamp faq