Linux MTD and NFTL - Question

[Sean Kelley]

I've been looking into an NFTL implementation for a device that uses a
NAND part and needs to be mounted on a Window's PC Desktop.  Thus I
need a Block Device interface so as to present a surface on which a
FAT filesystem can be placed.  However, in the course of my research
it came to my attention that a company called M-Systems has a hefty
amount of IP with regards to FTL and NFTL for pseudo-block devices. 
How does the Linux MTD-NFTL skirt the patents that M-Systems has in
place?  If I want to sell my product commercially what sort of risk? 
It is not terribly clear.  I've looked at YAFFS and JFFS2, but those
won't work if I wish to support USB mass storage for the Windows
desktop.

Any comments on NFTL and M-Systems patents much appreciated.

Thanks,

Sean