Latest version for Windows is Opera 12.17 (based on Presto). This version contains security patches, so I advise you to update your browser to 12.17.
Meanwhile, keep an eye on Opera Blogs. Opera is building a new browser based on Chromium/Blink, and Opera 12 will receive no more updates (other than security updates eventually). New functionality will be announced in the blogs. If the option to reload a page automatically is implemented again, you'll read it there.
Happy browsing!
