If 32gb isn't enough for you and you're willing to pay a premium, I can confirm that the SanDisk 64gb Class 6 microSDXC card will work with the Bionic. Got mine here
Amazon.com: SanDisk 64GB Mobile Ultra MicroSDXC Class 6 Memory Card with SD Adapter - Retail Packaging: Electronics
What I did:
1. Copy my entire 32gb card to PC (including any "hidden .??? files")
2. Power down, remove 32gb card, insert 64gb card.
3. Power up, ignore status bar message about SD card being damaged (if you see one).
4. Go to Settings > Storage. Mount SD card if necessary, otherwise just format it.
5. Copy back all my SD files to 64gb SD card.
Or you can just wait a few months as the price drops. Disclaimer: I'm not responsible if you bork your $150 sd card, even
if you follow my steps to the letter. Some people report you have to format the 64gb card on a PC first, but I was able to do it right on the phone.
EDIT: I forgot to mention: Bionic, rooted, 5.9.901, loads of bloat on ice