Adobe has just released ACR 7.1 and Lightroom 4.1 with enhancements, bug fixes, and support of new cameras, including the support for Fujifilm X-Pro1. However many reported conversion issues with the X-Pro1 (for example, this one).
For most users, the new version should definitely be a welcome update. It is quite a huge update though with 700+ megabytes download.
For users who have been having performance issues with Lightroom 4, here is a Lightroom performance tuning guide from Adobe.