OK this is getting better and better. It’s been some time since SPSS allows for custom dialogs to be set up which could execute R code within SPSS by simply pointing and clicking through the main menu. In this way, you can make R functionality available to users who have no knowledge of R or do not intent to invest on learning a command-line language. SPSS 23 comes with plenty of new built-in dialogs.
How-to
You need to install SPSS 23 together with R 3.1.0 and Essentials for R. No time to write a proper tutorial, but it wasn’t a tricky process at all. Got excited with the parametric IRT methods provided under Scale (see image below).