ARM has launched RISCV-Basics.com as a site to "understanding the facts" about the RISC-V architecture.
For those who came in late, RISC-V is open saucy and is being seen as a great white hope. So far though there has been one expensive developer board released.
Their five points it tries to make before designing a SoC is that the ISA accounts for only a small portion of the total investment to creating a commercial processor, RISC-V doesn't yet have a large developer ecosystem, there is the risk of fragmentation with this open-source ISA, RISC-V is new and thus not yet as mature in terms of being a proven architecture around security, and greater design costs with RISC-V due to potential re-validation if modifying the ISA.
Of course, then ARM tells us that its DesignStart service was "the fastest, simplest route to proven IP" and to design custom SoCs with confidence using their architecture. But then it would say that, wouldn't it?