> I'd actually like for Windows to start having a
> repository of software that it can install stuff,
Oh, like Debian.
> without admin permissions.
Actually, I think there should be a specific permission, "install software from approved repositories", which the sysadmin can grant to any user he chooses. (For home users who stick withe OEM setup, the OEM would be the sysadmin, so they could set it up so that the out-of-the-box user account has this permission if they think that's appropriate.)
> Yeah, I know everyone just winced and thought 'monopoly power',
It wouldn't have to be handled that way.
> but it should be an entirely free system to add new repositories.
> Simply a requirement that you be an actual identifiable person or company,
No, that would be bad, because Microsoft would be in the position to decide who's a real person or company, which immediately raises the spectre of the monopoly abuse scenario.
The correct solution is that the system administrator is responsible for deciding which repositories are approved and which are not. Anyone (well, anyone with an internet-connected server and adequate bandwidth) can run a repository, but users won't be installing software from it unless the sysadmin puts the repository on the approved list. Again, if it's an OEM setup, the OEM is the de facto sysadmin (unless the user starts making administrative changes, at which point they take on the sysadmin role themselves).
Microsoft themselves should run at *least* three different repositories: one for just Windows stuff, one for other (gratis) Microsoft software, and one for third-party (gratis) software that they approve and host. These should be offered at install time so that all the sysadmin has to do to approve them is turn on the corresponding checkboxes. (The first one, the Windows repository, should be checked by default.)
So if the sysadmin checks the box for "Microsoft - other free software", then some user finds out they need the Powerpoint Viewer, if the sysadmin gave them the install-from-repositories bit, they can install it without bugging the sysadmin.
The sysadmin should be able to open up the package manager, hit an "add repository" button (which might prompt for an admin password, depending on what kind of account you're logged into when you do this), paste in a URL, click OK, and voila, from now on any user with the install-from-repositories privilege should be able to install any of the software hosted on that repository. So then if OSDN decides to host a repository of open-source software, and if the sysadmin for a given computer adds it, then any user with the install-from-repositories bit set can cause any of the open-source software on the OSDN repository to be installed on the local computer.
For the interface, I'm thinking something similar to Synaptic, but perhaps with a nicer browse interface (larger entries that actually show a description of the package's contents right there in the list). Oh, and the list of packages would be simpler than Debian's, to wit, a particular piece of software would be one package, not twelve, because Windows users don't want to have to figure out which package(s) to select to install the console version of Emacs or the gtk version or the xaw3d version and whether to also include the elisp sources and so on. (Picking between XEmacs and Gnu Emacs is choice enough for Windows users. If they wanted lots of detailed options they'd switch to an OS that has more configurability. In a pinch, advanced users can still go outside the package system and download a more specialized installer or even compile their own.)
Obviously, the software on such repositories would have to come in some kind of standard package format, rather than arbitrary executable self-extracting install wizards as is the current custom. But that's not a big problem. The standard package format *could* include an executable phase, as some of the current package formats for other OS distributions do, as long as it's all standardized so that the package manager can do both install and uninstall fully automatically.