Now I see that a little link could have saved me time (and disk space ;-)) and maybe brought to GIMP some more beta testers. I can't understand the rationale behind this decision to hide the binaries.

I mean to cast no aspersion on Paolo here, I imagine he is correct that a few beta-testers are "put off" by the effort of compiling from source and that they might provide valuable feedback. Nonetheless, adding "some more beta testers" is not always a good thing. I think it does not take much inductive reasoning to foresee that hundreds of Windows users who don't know what a DLL is would soon inundate the dozen or so developers available who have to address problem reports. Many of these new beta-testers would have merely downloaded the "latest version" and have no idea what beta-testing entails (I have seen this happen in the past).

If someone, like Paolo, wishes to ease the burden of compiling development versions from source and still be able to contribute then I would suggest that he get together with some like-minded people, share a pre-compiled binary, and discuss amongst themselves the problems they encounter. Only one amongst the group would have to do the compiling and the group could work together to not only find problems but investigate solutions. In addition, the veteran members of the group could tutor the neophytes about the GIMP's development and create some truly worthwhile "beta-testers".

$0.02