Observations on interoperability between BISM Tabular and OLAP clients

Some of our customers asked me recently what will happen to their current OLAP investments now that BISM Tabular will be released in some months. As a consequence, I am becoming more interested in the impact BISM Tabular will have on existing OLAP clients. It is possible that client software use will drive user adoption on the server side; in other words, if DAX-only clients like PowerView (Crescent) become popular, there is a high chance the technology team will get some pressure to move on the direction of BISM tabular.