Assuming I ever get around to a database system, a timestamp tells you what's new, without the hassle of adding/removing "NEW" indicators.
Of course, if there was a more sophisticated system, I suppose the "NEW" indicators could be automated too, based on the timestamp, i.e. if it's older than a week or two.
Either way, though, unless I suddenly get a lot of free time (unlikely) or can pay someone that I trust to convert the entire site (while keeping it easy for my codephobic self), a site conversion isn't happening in the near future.
I have certainly thought about it, and I'm not opposed to it. It's just not on the horizon.