I'd like to use the hjkl keys to navigate the alt+tab menu.  This works in some websites already (like github.com) and I think it's a useful feature for those of us used to vim.  I don't think this would cause issues for the average user because when they alt+tab, they can use: the arrow keys/the mouse/alt+tab again to complete their search for the right window.  I also don't think this needs to go in a plugin because, as above, it's transparent to the average user.