In my view, the operating system is a basic but relatively decent database and organizational tool, and it's one that's given to you with your computer. Yes, it's limited. But it's the first thing that you, or one of your heirs, are going to have to deal with at some point in the future when trying to get a look at things. Yes, versions of today's popular digital photography cataloging or "workflow" applications that can open your catalog may still exist well into the future. But just as likely, they may not. Many databases and cataloging programs for desktop computers have already come and gone, not to mention device types and formats. So I'm going to argue that a simple chronological folder scheme in your operating system, and the raw photo files within those folders, should constitute the first thing you should focus on as the basic structure for your library.
When thinking about building an archive, it's important to look at the long-term stability and accessibility of the various pieces of the system. From here, it's looking like disc formats and operating-system versions are becoming more stable and seem somewhat more likely to have cross-platform and backward compatibility than today's cataloging and organizational tools have.
Starting to organize at the operating-system level might sound incredibly obvious to you, and I hope it does. But I'm always amazed at how many photographers fall for the thinking that cataloging product X will help you get organized.
In short, a catalog isn't your library! The files are the important thing. JPEG, PSD and TIFF are file formats that are very well understood at this point, and for that matter, CR2 and NEF formats are so ubiquitous by now as to be perfectly safe from an archiving standpoint. Many programs can and will be able to open them well into the future. But will you be able to open a version 2.0 Aperture vault or a version 2.4 Lightroom catalog 30 years from now? Perhaps, but it seems unlikely that those formats won't change or possibly even go away.
At this point you may ask, what about my RAW processing or developing settings? This is a valid question, so let's try to get it in perspective. Are the rendering choices that you may make today in your photo-processing application du jour going to change next month or next year? Is your distinction between four stars or five stars going to be important to your heirs years from now? Perhaps. But with time it will become much more important that they can make sense of your organization scheme to even be able to view your photographs! I'm not saying your rendering settings are not worthy of being stored. I'm just saying that they have their place, and they're not something on which to base your fundamental organizational structure.