Q: Does the ipad camera connection kit support microSDXC?

http://support.apple.com/kb/HT4101

Here are the  supported SD cards and image-transfer protocols:

• Picture Transfer Protocol                (PTP)
• Mass Storage Device                 protocol
• SDSC
• SDHC
• miniSD
• microSD
• MMC
• SDXC (supported only when not formatted as ExFAT)

plenty of more info on the page. So it kinda does but kinda doesn't support XC cards

From http://support.apple.com/kb/HT4101

Here are the supported SD cards and image-transfer protocols:

• Picture Transfer Protocol (PTP)
• Mass Storage Device protocol
• SDSC
• SDHC
• miniSD
• microSD
• MMC
• SDXC (supported only when not formatted as ExFAT)

You can use the kit to copy photos and videos to the iPad's Photos app, but the Photos app doesn't support all video formats, so some may copy over but you may not be able to then view them (you can't play iTunes purchased videos in the Photos app) - and you can't play content from the card.

Also if you are copying them onto the card from you computer then you need to create a DCIM directory off the root of the card, with the photos underneath it, and the photo/video filenames need to be exactly 8 characters long (no spaces) plus the file extension i.e. in a similar format as if a camera had created/written them.

It's not listed as being supported, but a couple of other threads imply that it will :

https://discussions.apple.com/message/20872115#20872115

https://discussions.apple.com/message/20602690#20602690

But it won't work if it's formatted as exFAT