Thanks William...your answer gave me back my peace of mind...i'm leaving during the night and i was really worry about it. i'm more a PC kind of guy and the shooting will be edit on FCP...so thanks man!!!
For full compatibility, you can reformat the drives as FAT32. The P2 cards are FAT32, so you'll have no transfer problems, and both Mac and Windows can read and write to them.
I'd be a little leery of Fat 32 on the Mac- limits the file size you can write to 4GB. If you are working with NTFS, get this program super cheap and gives you full read/write of NTFS drives on a Mac- even has an unlocked free demo: