The DeX Pad, an upgraded version of Samsung's DeX dock, uses your phone as a trackpad whenever it's attached. If you plug in a monitor and a keyboard (and a mouse, if trackpads aren't your thing) to its USB and HDMI connectors, you'll get a full desktop experience. One thing it didn't inherit from its predecessor that might disappoint you is an Ethernet port. But you can crank up its resolution to 2,560 x 1,440 pixels, whereas the max resolution you can get from the DeX dock is 1080p.
While it probably still can't compare to a real desktop computer, its higher resolution is great news if you want to play mobile games or watch a movie from your phone on a huge screen. You don't need to pre-order if you're unsure about getting the device, though: it will be available from Samsung's website and US retailers when it lands in the country in May.