Thailand's Export Promotion Department has "negotiated with the top management of McDonald’s in the US to add a Thai menu," according to department director-general Chantra Purnariksha. "Initially, the menu will be promoted in the western US, because of the large Asian populations there."
This agreement is said to be a result of Thailand's "Kitchen of the World" promotion.
I've e-mailed McDonald's media relations to confirm the story and they said they'll get back to me. I'll be following this one and will keep you posted.
UPDATE (11 Jan 2006): I received the following statement from McDonald's today:
"As a customer-focused company, McDonald’s is always looking at new ways to add even greater variety and choice for our customers. In that spirit, we talk with different companies and groups, including the Thai Ministry of Commerce. We are open to suggestions and future discussions regarding their menu concepts. However, it is very premature to speculate about any future outcomes."