Windows 7 is proving a divisive subject even in its infancy. One example: Last week, reviews from CIO.com's sister sites, Computerworld and InfoWorld, offered radically different opinions about what Microsoft has in store for the successor of Windows Vista, expected to ship in early 2010. Depending on where you look, Windows 7 is being called a savior for the embattled Vista, or a disaster waiting to happen. Regardless, certain interface features in Windows 7, whether brand new or streamlined, have been mostly applauded by experts who have tested the pre-beta. Which features are the most interesting and controversial? Here are five that deserve your attention: Revamped User Account Control Vista's well-intentioned security feature UAC (User Account Control), perhaps the operating system's most despised feature, became an easy target for Apple's "I'm a Mac" ads. Users were driven nuts by UAC's frequent pop-up prompts seeking confirmation before allowing programs to open.In Windows 7, Microsoft gives more control over UAC to the user, so there will be fewer prompts. If the user makes any of the changes that Vista has been prompting, such as changing the date or time, Windows 7 will leave it alone. In his review of the Windows 7 pre-beta, Computerworld's Preston Gralla commends the improvements made to UAC. "It rarely gets in your way\u2014you get a prompt only when a program tries to make changes to your PC. If you make them yourself, it allows you to go ahead." With Windows 7, Microsoft has dropped the "on or off only" approach of Vista and made UAC customizable. There will now be four settings: Never notify; only notify me when programs try to make changes to my computer; always notify me; always notify me and wait for my response.Improved TaskbarMicrosoft's new Windows 7 taskbar was demonstrated at the company's recent Professional Developers Conference, but was not part of the pre-beta software handed out to attendees. Still, and probably because it's not included in the pre-beta, it's one of the most-discussed features. Based on screenshots from the PDC demo, the new Taskbar has been given an overhaul. It does look notably similar to the Mac OS X dock, but reportedly includes unique enhancements such as the ability to display all running programs in a thumbnail list. If you hover over a thumbnail with the mouse, its full-size window will appear on the screen. In addition, mousing over a thumbnail turns other windows transparent to reveal the window you selected.Large icons in the Taskbar will launch programs, and you can rearrange the icons however you like. The Quick Launch bar of Vista will cease to exist and be incorporated into the Taskbar. Click here to view a demo of the Windows 7 desktop features.Time will tell if this is just lipstick on a pig, but the look, feel and functionality of the new Taskbar appears impressive. The Windows taskbar hasn't changed much in over a decade, so this redesign is long overdue. HomegroupHomeGroup is workgroup networking, but this time it's personal. It lets you easily link Windows 7 computers on your home network to share pictures, music, videos, documents and devices such as a printer. Homegroup is the most discussed new feature of the revamped Networking and Sharing Center in Windows 7. It is designed exclusively for home networks and won't appear if it's a work or public network. In order to setup a HomeGroup, a user's Network Location needs to be set as "Home" in the Network and Sharing Center.You get a significant amount of control with Homegroup; when you create a Homegroup, you specify which files, folders and devices you want to share, and create a password so that only people with that password can join the Homegroup. This way nobody, not even a friend, can hop on to your laptop and access your files or folders in Homegroup.Click here for a Homegroup screenshot from Computerworld's Windows 7 image gallery.LibrariesInstead of having files and folders organized under the familiar Documents folder, Windows 7 will feature separate Libraries for specific content types such as communications, contacts, documents, downloads, music, pictures and videos. Click here for a Libraries screenshot from Computerworld's Windows 7 image gallery.Each Library is stylized to fit its content. For example, the contacts Library shows phone numbers and e-mail addresses. The downloads Library lists the urls that each download came from.Better file organization is always needed, but Libraries are unique because they let you move folders from other locations on a network into a Library.For instance, if you have multiple PCs, and you want see all of your work files from all those PCs in one location, you can drag them into one of your Libraries. Those folders will still live in their original locations, but will also show up in your Library. Libraries can be shared with other people in your home network by using Homegroup. Click here for more on how Libraries and Homegroup work together.Touch-screen capabilityTouch-screen features on a smartphone are all the rage. But on a laptop or desktop? Microsoft is betting on it with Windows 7.At PDC, Microsoft demonstrated what multi-touch looks like on a PC. For example, the Start menu enlarges when you touch it. Another example: You may use your finger to browse through windows and Web pages. Whenever you press the screen, a water drop appears and the mouse cursor disappears, signaling that you're in touch mode.Click here for video of the Windows 7 touch-screen demo at PDC 2008.Veteran Microsoft watcher Mary Jo Foley recently blogged about her doubts that touch-screen functionality on PCs will take off. But the wheels may already be in motion as Jerry Shen, CEO of Asus, has stated that his company's netbooks will run Windows 7 and have touch-screen capabilities by mid-year 2009.