Today, Adobe released a new version of Lightroom. It comes in two flavors -- LightRoom CC which is part of the Creative Cloud subscription package and LightRoom 6 which is the perpetual license version. The CC subscription version includes LightRoom Mobile and the associated syncing function. The perpetual license version does not include those features. Otherwise, they are the same.
The big feature is the use of the graphics card for acceleration. There is a significant performance improvement, especially in the develop module. Of course, there are other new features. For example, you can do do HDR merges and stitch panoramas directly in LightRoom without needing to export them to Photoshop and the merged photos are stored as a 32 bit DNG raw file. Tagging now supports facial recognition. And the mask for local area corrections can be altered with a brush.
Jullienne Kost has posted some videos demonstrating new features.
LightRoom 6 (perpetual license) is $149 full or $79 upgrade. LightRoom CC plus Photoshop CC Photographer's subscription plan $9.99/month.