Can I disable window resizing from the top edge of the window in Lion?
Lion has (at least for now) the following preference keys:

AppleEdgeResizing (boolean)
AppleEdgeResizeBorderSize
AppleEdgeResizeCornerSize
AppleEdgeResizeCornerSizeNW
AppleEdgeResizeCornerSizeNE
AppleEdgeResizeCornerSizeSW
AppleEdgeResizeCornerSizeSE
AppleEdgeResizeExteriorSize




These can be accessed either with either the following commands:

defaults read DOMAIN KEY
defaults write DOMAIN KEY VALUE
defaults delete DOMAIN KEY


Where DOMAIN can be either -globalDomain to affect all apps, or a specific app's identifier e.g.: com.apple.TextEdit

Or edit ~/Library/Preferences/.GlobalPreferences.plist or other .plist file thereabouts, in Xcode or some other Property List editor.

Apps need to be restarted before they'll recognize any changes.