Excluding what Apple might do, I know of two connectors used for firewire, the miniature four pin connector and the full size six pin connector.  My experience, cameras, etc, seem to use the miniature 4 pin connector where desktop computers use the full size six pin connector.  Laptops I've seen use the miniature 4 pin connector.  You can buy cables of both combinations, 4 pin to 4 pin, 6 pin to 6 pin, 6 pin to 4 pin.  Check with your favorite computer store, they should stock them all.  They come in all different lengths too.

Hope this helps -

Jim