Two interesting things to note:
andThis new release also unifies the Artist and Studio edition into a single powerful yet affordable version with unlimited multi-core capability. Artists and studios alike will have access to all the advanced RenderMan features such as RenderMan shaders and RIB import/export.
The feature overview and all other info can be found hereThe downloaded software comes with one full license for free with no restriction for commercial use and is not time limited. A maximum of one free license is available per customer. This free version has all the features and is only limited in performance by using a maximum of 2 cores during rendering. Which means on computers with more than 2 cores (or CPUs), the software will not use all the computing power available.
edit: added the missing "beta" to the title