Jos de Bruijn points out new In-Memory OLTP features introduced since CTP3:
Large object (LOB) types varchar(max), nvarchar(max) and varbinary(max) are now supported with memory-optimized tables and table types, as well as natively compiled T-SQL modules, and the size limitations mirror that of disk-based tables (2GB limit on LOB values). In addition, you can have a memory-optimized table with a row size > 8060 bytes, even when no column in the table uses a LOB type. There is no run-time limitation on the size of rows or the data in individual columns; this is part of the table definition. Of course, all data does need to fit in memory.
I’m very pleased about this—now I can go back and turn some of my bigger table types into memory-optimized table types.