it wont work... http://www.sdcard.org/consumers/faq/#sdxc_compat


Is SDXC compatible with existing SD devices?
Existing SD and SDHC devices are not be compatible with new SDXC memory cards, but existing SD and SDHC memory cards will still continue to be offered by card manufacturers for the foreseeable future. Existing SD and SDHC memory cards will work in SDXC devices.