What is this nonsense about the number of files slowing the system down? Surely seeking to a bunch of little libraries is slower than loading one file initially, but does it matter in the long run? Once you're up and running there should be practically no noticeable difference, right?
I can't imagine that the number of libraries is what's slowing Vista down... rather, it's just what those libraries are actually doing.
I've seen people who have never heard of "folders" save 50-60,000 items in one folder. NFTS (if they keep it), slows to a crawl every time that folder's accessed because I don't believe its storing the entries in a tree.
The other possibility is all of the memory mapping of hundreds of little libraries into the system plays havoc with code locality and L1, L2 caches in microprocessors. Since Vista is trying to be "more secure", there are probably more monitors and validation between these address spaces than there were before.
Now with Vista on just "what the libraries are doing", maybe they just turned a bunch of interns loose on a bunch of API's embedded in those libraries and they did the "almost simplest thing" that could possibly work without thought to performance. "Get it working and ship! Optimize it later."
I find Vista a nuisance to users who complain that nothing looks the same and the "trivial" modifications of user-interface derail the "learned-by-rote" user.
Microsoft would do the world a gigantic favor if they just conceded and made the world "Microsoft Linux." Apple did the right thing already with adopting a "UNIX" core to base their systems and and put all the money into UI and feature improvements. Microsoft is spending too much time overworking their engineers who work on continual bomb squad responses to exploding deck chairs to focus on usability for users.
I call BS. The trouble Microsoft has had with Vista would be nothing compared to the trouble it would have if ALL applications had to be recompiled to work with Windows 7. The article cites no sources and doesn't offer any substantiation at all for its claims.
The article didn't say that everything had to be recompiled, but that they could. Without recompiling apps can run in a virtualized, compatible environment (like Classic on OSX). It didn't cite sources, but MS has alluded several times to this being the plan.
As common as virtualization is becoming , that could be a good solution as long as they can keep a ceiling on the memory cost -- true virtualization can be really expensive, memory-wise.
On the other hand, if they're simply talking about a conventional compatibility box, this is less of a worry -- Windows has been doing variations of this for years for backwards compatibility -- since long before OS X.
This article skips past all the technical details, but the smartest solution might be to make the new API purely managed (i.e. .Net), and run all unmanaged apps in a compatibility box. This is great for stability, and it ends the days where you have to dig down into C or C++ and mess around with window handles to use certain OS features that aren't available otherwise.
I can't imagine that the number of libraries is what's slowing Vista down... rather, it's just what those libraries are actually doing.