I started to tweet Contact Form 7 release announcements on my Twitter account. However, as I usually tweet in Japanese, you may feel it boring. So, if you want to read only the news of Contact Form 7 in English, I suggest you to check #contactform7 from @takayukister (feed), instead of following me.
I’ll tweet release announcements about a week before I release the new version. You can download the prerelease package from here (you can find “Development Version” at the bottom). If you think of translating the latest Contact Form 7 and you can send me the language files before the release date, I can include it in the package to be released.