There is a new SCN blog describing an additional option for warm data within BW-on-HANA. Fundamentally, it allows to define a number of nodes that hold more RAM (memory) and that can be filled with more data that normally allowed. BW-on-HANA is able to manage this kind of “overload” as it is “warm data aware”. Read the blog for details.
In the meantime, Klaus has published another blog with additional details. Worth while reading!