By Prince McLean

Published: 07:00 AM EST

Amid all of the new features highlighted Monday in Snow Leopard, iPhone 3.0 and Safari 4.0 were a few unpublicized retractions: Safari 4.0 has lost its "tabs on top" and returned to the old conventional tabs of the previous 3.0 version, while all mention of full ZFS support in Snow Leopard Server has been scrubbed.

When Safari 4.0 was released for free download yesterday, its provocative use of upward facing tabs was dropped along with its beta label. For users who just got used to having their window tabs tucked into the dead space in the menu bar, the change back might seem disappointing. After all, Apple promoted the idea of 'tabs on top' as a clever way to minimize the impact of user interface elements on the browsing experience, a key design goal of Safari since its first release.

Why have tabs dropped back down to consume an extra strip of interface real estate? Perhaps the company though it was too confusing to new users, or that it simply wasn't consistent or compatible with its own interface guidelines or those of Microsoft Windows, which the company is now trying to look native on with Safari rather than imposing its uniquely metallic Mac appearance.

Whatever the reason, the retraction of the bold design step by the typically safe, if not conservative, company is slightly disappointing and makes the new browser seem a big dowdy. Users might forgive this due to Safari's enhanced rendering speed. The new-old tabs also still work the same, featuring the intuitive drag to reorder capability and the option to drag a tab outside the current browser to spawn a new window, or to drag a tab into an existing window to make it a component tab. Apple claims 150 other features for Safari in its place.



The conspicuously missing ZFS

The announcement of new support for Sun's open source ZFS in Leopard drew a frenzy of attention that had pundits insisting that Mac OS X would quickly make the new file system its default in place of HFS+, a prediction that has not materialized.

Of course, while ZFS is positively dripping with easy to understand feature buzzwords, there's no desperate, impending need to replace HFS+ nor any likelihood that ZFS would really offer consumers, who make up the vast majority Apple's target market, any tangible benefits. For starters, the features of ZFS only really get started when you're using multiple disks, and most of Apple's users are now buying notebook systems, none of which ship with multiple drives.

Still, ZFS seemed to hold a lot of promise to Snow Leopard Server users, who might want to take advantage of the new file system's support for features such as flexible volume management, continuous data integrity checking and automatic repair.

ZFS was formerly listed prominently among the scant new details offered on Apple's next version of Mac OS X Server, but now the company's entire site seems to be purged of any mention. Sources have noted that the feature was pulled from the user interface of Disk Utility in recent developer builds.

While Apple probably isn't abandoning the technology, it has certainly slipped from the list of critical to deliver features for Snow Leopard. The only mention of ZFS in the search results of Apple's website is its inclusion as an open source project in Darwin. Well, there's always Mac OS X 10.7.

Sometimes, Apple drops an advertised feature when it is discovered that it simply isn't ready for mainstream users yet, as was the case with Time Machine backups to AirPort. In other cases, the company has dropped a planned feature to rethink how to implement it, as it did with Push Notifications for iPhone 2.0 last fall. In both of those cases, the technology was eventually reinstated for release. In other cases however, a dropped feature might never come back. Apple never revisited the idea of customized user interface themes, for example.