Today Adobe released a free beta version of Lightroom 5 that you can install alongside your current production version. Adobe usually has a beta version for major Lightroom updates where they accept user feedback and let users "kick the tires" for a few months.
There are a bunch of cool new features in the beta for you to try(the links below are to Julianne Kost videos explaining the new features:
For real estate and interior photographers the feature that grabs your attention as the most significant is upright (#3) which is a major improvement to straighten tilted images with a single click. Upright analyzes images and detects skewed horizontal or vertical lines. You choose one of four correction methods, and Upright can even straighten images where the horizon is hidden.
As Julianne explains, this beta version of Lightroom 5 won't convert your Lightroom 4 catalogue you have to create a new catalogue of images to use with Lightroom 5 (but the final release will). Also, this is a beta application so don't use your original images; use copies.
Also, you can ask the developers questions or give them feedback on Lightroom 5 beta release at: forums.adobe.com/community/labs/lightroom5/.