Edit: Fork compatible with new versions of Firefox Bewertet mit 5 von 5 Sternen

Edit: You can no longer simply apply the patch because it breaks the signature. I forked the add-on, you can download it here: https://addons.mozilla.org/firefox/addon/pasteontonewtabbuttonevived/

Nice add-on, missed that feature (Fx Bug 694825) when coming back from Chromium.
The add-on stopped working with Fx 25 due to an API change (https://blog.mozilla.org/addons/2013/09/30/compatibility-for-firefox-25/), but this patch (might not be the best one, though) makes the extension work again:
8,10c8,12
< url = window.getShortcutOrURI(url, {});
< if (!url)
< return;
---
> try {
> window.makeURI(url);
> } catch (ex) {
> Cu.reportError(ex);
> }
16c18
< window.openUILink(url, event);
---
> window.openUILinkIn(url, "tab");