The biggest deal about NTFS isn't security, even though that is a large part of it. Its the fact that its a journaled file system and that there is a redundancy in the file system itself that makes it very fault tolerant. IMHO use FAT32 only if you absolutely have to. I currently use macdrive in my Windows XP partition to read the OS X partition and leave all my data files on the OS X side of things while still befittingly from NTFS in Windows.
I'm really kind of sad that Apple hasn't taken NTFS support beyond the ability to read. And I hope that the ability to write will show up in Leopard as a last minute feature.