Aaron Butacov

It adds a simple month-by-month calendar that shows all the months you have future posts for (and the current month no matter what), it highlights the days you have posts for, and as an added bonus if you click a day, the Post Timestamp boxes change to that day, month and year.
Also includes a widget so you can show users what upcoming posts you have on your website.
If you want to ad a widget to your dashboard, uncomment the line <code>add_action('wp_dashboard_setup', 'fpc_setup_dashboard_widget');</code> in the future_calendar.php file.

Future Posts Calendar

This plugin adds a monthly calendar that shows all the dates you have future posts.

Nicholas Pickering

Adds Future scheduled posts to preview pages, so you can preview what your site will look like before the post goes live.
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[Fork the plugin on <a href="http://github.com/2nickpick/ss-homepage-preview" title="GitHub" rel="nofollow ugc">GitHub</a>

SS Homepage Preview

Adds Future scheduled posts to preview pages, so you can preview what your site will look like before the post goes live.

Future Posts Calendar vs SS Homepage Preview