Tested says that there are some pretty major hurdles to jump over:
There are no physical buttons aside from the redundant home button. The TouchDroid devs have indicated that in their initial Gingerbread build they will have to roll their own on-screen controls. We expect this solution to be a bit of a kludge; Gingerbread is not designed to effectively run apps with on-screen buttons.
You may be wondering why they don’t just go straight for Honeycomb. The big issue here is that Honeycomb is not open source. Sure, there are ways to yank the code off a retail device and pull it apart, or use the SDK as a base. There is a Nook Honeycomb build after all. But it’s not ideal, and the TouchPad is not an Android device by nature. The TouchDroid project is probably hoping for ICS to drop soon.
The next hurdle will be that screen. The TouchPad uses a 4:3 resolution (like the iPad), and almost all Android tablets are widescreen 16:9. The only Android tablet of any note that is 4:3 is the Vizio Tablet. This device runs Android 2.3 with a heavily modified interface. A lot of work was done to make it run correctly on that display. Android 3.2 added better support for different size screens, but since it isn’t open source, the prospect for 4:3 displays is murky.
… Android may not have driver for some of the more esoteric components sourced by HP. Android tablets might use different accelerometers, gyroscopes, touch screen controllers, cameras, and brightness sensors. If there is no place to get the drivers from, developers will have to create them. That’s going to take time, and the results might not be ideal. As an example, the TouchPad uses an LG panel with Cypress Semi touch controllers. We couldn’t find an Android tablet that uses those parts.
Much more in the article.