This is one of those tablets that I plan to make time to see when it hits store shelves. It last showed up around the time of CES 2011. According to those lucky enough to see it, it's based on a10" multi-touch display.
The eeePad Slider is running Honeycomb on a Nvidia Tegra 2 CPU (much like the eee Transformer), and it has a pari of camera (5MP & 1.2MP), USB host, a card reader, and Bluetooth. I'm assuming it also has Wifi (n), but it doesn't appear to have been tested.