Inside OS X 10.8 Mountain Lion GM: Safari 6 adds iPad-style iCloud-shared tabsSafari turns 6 in this summer's release of OS X Mountain Lion, offering a new view of open tabs similar to iPad and a new iCloud tab-sharing feature, along with an offline Reading List, new website passwords browser, new privacy settings, and a feature that allows websites to send alerts to the new Notification Center.
Apple's latest build of Safari 6.0 builds upon features previously outlined for what was originally called Safari 5.2, which brought a unified new user interface with one field for both Web, bookmark and history search as well as for directly entering a URL. That change also removes the SnapBack button and creates room for an always-visible Reader button.
Safari's new unified user interface, anti-phishing URL highlighting, emphasized Reader feature and prominent Share Sheet features (all depicted below) were detailed earlier in the year, but Apple has continued to work on its browser in the months since.
New iPad-style tabs
Safari 6 introduces a new Exposé-like tab view similar to that already available on iPad. Click the "Show all tabs" button in the Tab Bar, and you can visually review what's going on in each open tab, flicking between the scaled-down open tabs within the browser window, and clicking on any one of them to make it the current tab.
iCloud sharing of open tabs
Apple has also introduced a new iCloud sharing feature that enables Mountain Lion Safari 6 users to share open tabs between systems that use iCloud. Clicking on the new iCloud icon in the Toolbar presents a popup that states "iCloud automatically shows all the open tabs on your other devices."
Once you have multiple iCloud-connected Macs using Safari 6, however, you'll get a popup that includes all the active tabs you have open on your other computers. Apple hasn't yet made any announcements about bringing this feature to iOS but it seems very likely that it will eventually appear there, too.
On Topic: Mac OS X