The documentation says
"Using Samba, 2ed, O'Reilly & Associates (Feb. 2003). (Jan 2007: The 3rd edition has been released and will be available online soon)."
But it's now April 2009, over two years later than the date in this snippet.
In general it is wise to avoid built-in obsolescence in documentation, so that for example we don't find ourselves asking why Windows 95/98/ME/NT/2000 are referred to in the smb.conf man page as "modern clients".
Avoid any expression which refers to things as they are 'now'; and avoid the use of the word "today" at all costs. "At the time of writing" is permissible for the state of the software and utilities being documented and perhaps when discussing scientific knowledge (although one wonders what place there would be for such a discussion in the Samba docs); but this expression should not be used to describe other software such as operating systems and clients.
This is not really a docs bug, it's a comment on the use of language on the site, which is a fair criticism. We do use dated language like this frequently, and don't go back to update it.
I'll change the language on this line.
This bug as it stands was fixed by Deryck Hodge in 2009.
That we still have the link at all is a separate bug.