I got my X-Pro1 3 days ago. Unfortunately I´ve the same problem. Not only that raw files aren´t supported, strange is that some jpgs are imported and others are not!
In the meantime I use the following method: import with phaseone media pro (former Iview mediapro) into an existing folder of lightroom and then refresh the folder in LR4. This results in at least showing all jpgs but still doesn´t import the raw files. As I also use CaptureOne for my Pentax 645d files (as DNG´S no pef support
yet) MediaPro renders the files with the C1 engine. Surprisingly MediaPro also shows a perfect preview of the raw files although C1 doesn´t support the Xpro1 yet