? Sorry, don't get the point?
http://graphicall.org/gimp is the link for the Gimp-builds
http://graphicall.org/gimp/windows or
http://graphicall.org/windows/gimp are the links for the windows gimp builds.
Add "/32bit" somewhere in the url, maybe in the end, middle or as first after the domainname, and you only get the 32 bit builds.

But easier to use is the selection interface on the sites left handside.

You say I should look for the "new board" for several recent builds - maybe you meant the "gimp news" section of the board. I can only find Parthas Builds there. Anyways, its a mess to have to look inside a forum to find these builds.
There seem to be other people being able to build gimp for windows, as Onkel Hatti or Rod. But these guys don't seem to have interest in running an own site for publishing their builds, so a service to provide space for custom builds seems promising. Graphicall.org is quite easy to use. You can have a diskussion for the desirede build, and can document some glitches right on the place.

Hm, I really start to sound like an advertising troll for graphicall.org. Well, the site is a community driven thing (as far as i know), and i don't have anything to do with it except as a user. But it really works great for Blender, and I am missing something comparable for Gimp. I realy like to suggest using graphicall.org for more Win-Gimp-Builders around. So please, use it!

maddes

What about compatibility with the plug-ins ? I've read all the API were broken with latest 2.8.
Any chance to get G'MIC working on 2.8 ?

Umpf, sorry, now I've seen: I wrote "some people already sucessfuly built blender for Windows?" . Should read "some people already sucessfuly built Gimp for Windows". Changed it. Sorry, typo. Didn't make any sense.
maddes

Gimp-2.7.6 gives you a chance on install to allow compatibility with older plug-ins.

Has anyone tried GMIC with the Gimp-2.8 RC1 release?

David
2.8 should no worsen any compatibility issue with plugin, if working with last 2.7 they should work also in 2.8 and GMIC works well with gimp-2.7
Hopefully instead in 2.8 should be included also a sort of compatibility layer ..but anyway that should not involve gmic

In theory , better wait some test (also because the changes in several libraries ) but the change you fear are planned for 3.0 or later