Win+Space operates as a keyboard shortcut for Aero Peek.
Win+Up and Win+Down are new shortcuts for Maximize and Restore/Minimize.
Win+Shift+Up vertically maximizes the current window
Win+Left and Win+Right snap the current window to the left or right half of the current display; successive key presses will move the window to other monitors in a multi-monitor configuration.
Win+Shift+Left and Win+Shift+Right move the current window to the left or right display.
Win+ + and Win+ – (plus and minus sign) zoom the desktop in and out.
Win+D – Toggle showing the desktop
Win+E – Run Windows Explorer.
Win+F – Search window.
Win+G – Displays all the Gadgets above other windows.
Win+L – Lock the computer.
Win+M – Minimize all open windows
Win+Shift+M – Undo all window minimization
Win+P – shows external display option selector
Win+R – Open Run command.
Win+S – OneNote Screen Clipping Tool
Win+T – provides keyboard focus to the taskbar, then cycles the keyboard focus through taskbar items. (Win+1 through Win+0 provides shortcuts to the first ten pinned taskbar items
Win+U – Open Ease of Access Center.
Win+X – Run Windows Mobility Center.
Many of these shortcuts work on Windows Vista and Windows XP too!