Want a tablet that's so open, you can install any OS you want onto it? Set your sights upon Axon Haptic, whose hardware was designed to work with almost any OS you want, including Windows, a variety of Linux flavors and OS X. Yes, you can hackintosh it to your heart's content.
Created by Axon Logic, the tablet uses an EFI bootloader that allows it to be compatible with any variant of Darwin OS, which encompasses a number of Linux distributions, as well as Apple's OS X. For the hackintosh part, it essentially tricks the software into thinking it's running on Apple hardware, something more netbook manufacturers should be doing on their machines.
The Axon Haptic is, for all intents and purposes, a netbook crammed into a tablet shell. Core hardware consists of a 1.6GHz Atom N270 CPU, a 10-inch resistive touchscreen (1024 x 600 resolution), 2GB of RAM and a 320GB HDD. For connectivity, it comes with both WiFi and a 3G SIM slot (compatible with AT&T and Verizon). There's also two 200-pin SO-DIMM slots, built-in speakers, a 1.3-megapixel webcam, a removable battery (3000mAh, good for 3 hours or less) and a number of ports (3 USB, audio I/O, VGA, microSD and ethernet).
Obviously, running what's essentially desktop OS on an overachieving tablet isn't likely to deliver the best user experience. However, we have no idea how much testing the company actually put into the design, so there might be hope. I can imagine hardcore tinkerers grabbing this even just for the multi-boot capabilities, although it will probably have a hard time convincing more casual users.
Pre-orders for the Axon Haptic have opened. You can secure one early for an optimistic $750.