The Model Context Protocol has rapidly become the default way LLMs connect to tools and data — but as adoption accelerates across vendors (Anthropic, OpenAI, Google, and dozens of platforms), the open-source community faces a familiar risk: fragmentation through vendor-specific extensions that quietly break interoperability. This talk looks at what's needed to keep MCP genuinely open as it scales SDK conformance across implementations, the role of open governance now that MCP sits under the Agentic AI Foundation, and where early cracks in cross-vendor compatibility are already showing up. We'll walk through concrete examples of interop failures between clients and servers, and what the ecosystem is doing (and should do) to prevent MCP from repeating the fragmentation seen in past "open" protocols.