I have now installed 1.08 and tried out the Palm's Universal Wireless Keyboard and it works OK for my limited requirements. I only use it to type in Doc to Go (word processing) and all the typing keys work and some of the Fn (function) keys work to open the menu options, rotate the screen and so on. I have not tried every function to make a list of what works and what didn't but I am happy with what works for now...
Therefore, I would rate the level of functionality to be about 98% (for me) for Universal Wireless Keyboard with Palm TX. Others may find that they have other requirements in other apps and the level may be lower. In any case, I would assume 95%+ functionality for most people.
So don't be like me and leave the keyboard in the original pack (just in case Palm don't release an official Palm TX driver, I was going to sell it), use it, it is still fine for most work (without the TX driver).