Unfortunately not. The fork complicated things a bit. On Hudson I am currently no longer able to release because the release procedure has changed quite a bit.
As for jenkins, the layout has been changed recently. My JSON file was actually hand written, but it seems you're supposed to generate it automatically.
As a workaround you can use a custom JSON file as described on the plugin wiki page. If I have a few spare minutes next week I can create a JSON file for 3.7 and attach it to this issue to make it easier for users.

For Jenkins I will query the dev mailing list to find out how to put a new version of the buckminster.json online, but for Hudson I think I'll wait until it's clear how the Eclipse proposal will affect the infrastructure and release procedure.

OK, thanks! It's actually not really that hard to manually set up a Buckminster instance but of course anyway to reduce the administrative burden is always good.

We can stage the new json file very easily. Just give us a new file and it'll be done.

This is finally fixed

I've setup a crawler (https://github.com/jenkinsci/backend-crawler) that periodically generates a json file with also recent releases (including 3.7 and 4.2); the crawled json file is taken from here https://github.com/jenkinsci/buckminster-plugin/blob/master/updates/buckminster.json

you can now select also 3.7 and 4.2 versions of Buckminster to install