Apple's yearly developer conference should see iOS 8, OS X 10.10, and likely some hardware.
iCloud Website Error Hints at Upcoming iCloud Bookmarks Feature
An online iCloud Bookmarks section, if added to iCloud, could be useful for users that wish to access their bookmarks on a computer that is not used regularly. While iCloud already syncs Safari bookmarks between Macs and iOS devices, iCloud bookmarks are not currently accessible via iCloud.com.
First discovered by a Twitter user (via 9to5Mac), the iCloud Bookmarks page can be seen briefly when visiting a specific URL, originally accessed by installing the Chrome extension from the iCloud Control Panel for Windows app on a PC: http://icloud.com/bookmarks_extension
Though the page text suggests that an iCloud Bookmarks feature could be in the works for iCloud.com, it is possible, based on the "extension" URL, that it is referring to an iCloud Bookmarks extension, but iCloud browser extensions for both Chrome and Firefox on Windows have been available for several months following the launch of iOS 7.
As noted by 9to5Mac, the introductory screen also features the iOS 7-style design for Bookmarks, which seems to indicate that it was rather recently created, pointing more towards a new feature than an old page for an existing feature.
Apple has been hard at work beefing up iCloud during the last year. At WWDC, the company introduced iWork for iCloud, giving users a way to work on collaborative documents from any device, and more recently many of the apps received a full iOS 7-style redesign.