The problem with the old netscape base was, it was hopelessly jumbled. It had been added to and extended, all from the Netscape 1.0, with little cleaning or maintenance. The point of web browsers in this era was "as big as possible, as fast as possible", and the result was some huge piece mass of code noone could keep track of.
So the new project had make a new design from scratch, adding in pieces of code from the old Netscape where possible.
No one wants to work on the old netscape code anymore, because it was a nightmare.
(Microsoft is experiencing the same kind of problems, btw. Except their
philosophy has been "As much income as possible for the least expenses possible.")
If you want to be on the bleeding edge, also in stability in some ways, try out Mozilla
. What Netscape does, essentially, is pick up a version of Mozilla they like, add some Netscape & AOL stuff of their own, and release it as netscape. That's okay, because the Netscape folks do a lot of the work behind Mozilla.
The other part of the Netscape/Mozilla colloboration is the open sorce folks, who take the pieces from Mozilla they want, and make it into a flurry of browsers for different purposes. The open source folks excels at bug reports, debugging and interesting new additions, so it weights out well.
Mozilla almost exclusively works on optimizations and stability by now (they're nearing their official 1.0 release, which I guess is parallel to Netscape 7.0), so I don't think it's any more dangerous than Netscape.