The AI arms race has officially shifted from raw language models to something far more dangerous—and far more useful: multi-agent systems. In the last week alone, xAI dropped Grok 4.2 beta and Anthropic rolled out Claude 4.6 upgrades (Sonnet as new default, Opus with 1M context + agent teams). These aren’t incremental LLM bumps. They’re full architectures built for collaboration: agents that debate, specialize, critique, and synthesize like a digital research team on steroids