OpenAI is in talks to lease a massive, proposed 10-gigawatt AI data center campus on federal land in Pike County, Ohio, from SoftBank's SB Energy. The entire complex, if fully built out, could cost at least $500 billion. And here's the kicker: Nvidia is reportedly discussing using its massive balance sheet to backstop OpenAI's lease and SB Energy's future financing. If the deal goes through, it would become one of the largest corporate real estate commitments in history.