this will require moving tracker to extra because it will become a makedependency,
but IMO tracker deserves to be in extra (I could maintain it). ;)

Do we have a standalone libtracker package (or any dbus method that nautilus should use instead of these broken library implementations)? I don't want nautilus to depend on the full beagle and/or tracker package.

Debian have similar questions:debian-gtk-gnome@lists.debian.org/msg12959.html"> http://www.mail-archive.com/debian-gtk-gnome@lists.debian.org/msg12959.html
Ubuntu seems to want to stick with tracker only: https://wiki.ubuntu.com/IntegratedDesktopSearch
There is an effort to create a single specification:
http://www.freedesktop.org/wiki/Specifications/shared-filemetadata-spec
http://www.freedesktop.org/wiki/XesamHeader
the metadata spec is implemented by Tracker and some other projects moving the same way.
Personally, I don't like Beagle just because it's in C#.

Looking at the nautilus PKGBUILD in abs, I noticed that that there is a beagle patch. I'm not sure what it does. However, if I install beagle, nautilus is integrated by default.

Ubuntu has a libtracker deb, and nautilus is compiled against it. The full tracker is not required to be installed. I agree that these programs should be detected and their API dynamically loaded instead of statically linked. My guess is that in the future, everything will use XESAM (a common search engine API). Tracker does not have an implementation yet. Beagle does, but we do not have it. It's just a library. GNOME-Do does have a XESAM plugin. Meaning, it can use beagle. A few other programs have started to use xesam as well.

The beagle patch is to allow compilation with beagle 0.3.x, as they changed API in that and Nautilus only supports 0.2.x.
At this moment, nautilus links to the libbeagle.so and libtracker.so libraries provided by either libbeagle or the tracker package. Having a dependency on libtracker as a standalone package is not a problem.
Having a dependency on either beagle or tracker itself is problematic: they put desktop files in the autostart folder, so when you install it and don't use it, it gets started by default.

If we want tracker support (and I think we want this), please provide a libtracker package and a tracker package that excludes this lib. I'm willing to add support for tracker to nautilus, but I don't want to maintain tracker (I have more than enough pkgs already).

libtracker is in testing for amd64 now, totem and nautilus have support for it now.
This will lead to file conflicts with the AUR tracker package, but we'll adopt it into extra very soon anyways.