It seems that, as of February 2008, Netscape Navigator will no longer be developed. Netscape may not be popular any more (certainly nowhere near the ~80% share they had in their heyday) but the Mozilla project owes a hell of a lot to the original Netscape codebase.
Netscape are recommending that all remaining Netscape users should move to Firefox – sensible advice :)
So, farewell Netscape, commendations for playing a big part in the spread of the Internet (even if the 4.x browsers were often a real PITA for web developers), and RIP.