MacBidouille reports that the next version of Mac OS X (10.3 aka Panther) will feature a new file system format akin to BeOS's file system.
Previously, it was reported that Dominic Giampaolo, a BeOS engineer was employed by Apple approximately one year ago, and it is presumed that his experience with BeOS's journaled file-system was applied towards Apple's current implementation of Journaling in Mac OS X. If this newest rumor is true, more BeOS file-system features may find their way into Mac OS X.
This 2001 article by Scot Hacker entitled "Tales of a BeOS Refugee", gives one experienced BeOS user's perspective on the advantages of the BeOS file system.
MacBidouille also claims that Mac OS X 10.3 will feature significant performance boosts over 10.2.