Windows 8 Hybrid
Sure it's a lot bigger than a tablet, but I think these devices are going to be very important because they bridge the gap between the PC of the average user (a basic laptop) and the tablet of the average user (an electronic entertainment slate). These devices can perform BOTH functions and they use one operating system to do so. That's very impressive in my book ... err tablet.
Marc touched on this, but I think these devices and technologies will develop into a better combined technology in the future to replace both. I think touch will be central and even though I am partial to using a stylus, I think it along with the mouse and keyboard will soon be gone, and a convertible/hybrid device like the XPS 12 is going to be a key transition tool.
I worry that, because hybrid notebook/tablets were once lame, too many are holding dogmatic positions on hybrids. Sure. Hybrids were lame for just about everyone until recently. However, it is foolish to assume that is going to be the case with Ivy Bridge Windows 8 touch optimized convertibles; and probably dead wrong when it comes to Haswell-based convertibles - where the size and weight differences may not be nearly as great as they are now between the best tablets and a hybrid device.
However, the real winner may be the Surface Pro type of tablets (Intel or AMD x64 CPU) from third-party vendors - the ones that wisely provide desktop docking options. These should be great for business users that roam between home and any number of main or branch offices. Admittedly, it may be less ideal for a mobile sales force - where a convertible may make more sense due to an absence of docking stations at client offices.
For purposes of completeness, I don't want to discount tethering a tablet to a Bluetooth keyboard and mouse (or touch pad); but I question how often "normal" users actually use this sort of setup. It seems far less convenient than a hybrid; and, for that reason, I wonder how often a typical user would go through the trouble of pairing the peripherals (never mind remembering to bring them along!). That said, I'll bet this is the preferred option for many gdgt users as Bluetooth pairing is nothing more than a trivial inconvenience for the tech savvy.
One last observation about touch interfaces and convertibles (or tablets with keyboards), I find touch interfaces awkward as soon as my screen is docked or mounted in a stand and I have a physical keyboard to interact with. Specifically, I hate reaching up from the keyboard to interact with a screen mounted in a more vertical plane. A large touch pad (that is gesture aware) seems preferable to a touch sensitive screen in this mode. Maybe this is just me . . . and a decades old mouse habit.