We apparently have few Macworld magazine subscribers here. I refer you to the back page (pg.96) in the July 2010 issue. John Siracusa talks about the future of OS X, and the need for a modern file system in light of the fact that HFS+ (still used in 10.6.x) is more than 12 years old, which is based upon HFS which is 25 years old.

Here is the complete article:

http://www.macworld.com.au/blogs/apples-other-operating-system-5059/