@LH, that number does mean something... just how much of W7 you can use or what performance you can expect. Yes, YMMV, and actual results do count, but at least one has a 'figure of merit' so to speak to talk about.
This is MS's 'help' on the subject :
The base score represents the minimum performance of your system, based on the capabilities of different parts of your computer, including random access memory (RAM), central processing unit (CPU), hard disk, general graphics performance on the desktop, and 3‑D graphics capability.
Here are general descriptions of the experience you can expect from a computer that receives the following base scores:
A computer with a base score of 2.0 usually has sufficient performance to do general computing tasks, such as run office productivity programs and search the Internet. However, a computer with this base score is generally not powerful enough to run Aero, or the advanced multimedia experiences that are available with Windows 7.
A computer with a base score of 3.0 can run Aero and many features of Windows 7 at a basic level. Some of the Windows 7 advanced features might not have all of their functionality available. For example, a computer with a base score of 3.0 can display the Windows 7 theme at a resolution of 1280 × 1024, but might struggle to run the theme on multiple monitors. Or, it can play digital TV content but might struggle to play high-definition television (HDTV) content.
A computer with a base score of 4.0 or 5.0 can run new features of Windows 7, and it can support running multiple programs at the same time.
A computer with a base score of 6.0 or 7.0 has a faster hard disk, and can support high-end, graphics-intensive experiences, such as multiplayer and 3‑D gaming and recording and playback of HDTV content.
If a particular program or Windows 7 experience requires a higher score than your base score, you can upgrade your hardware to meet the necessary base score. If you install new hardware and want to see if your score has changed, click Re-run the assessment. If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
What I find interesting is "If a particular program or Windows 7 experience requires a higher score than your base score, you can upgrade your hardware to meet the necessary base score.". Now I have not read many s/w boxes recently, but I never recall seeing any rating like this on boxes or web pages? Maybe something MS 'wished for' and never happened.