Microsoft has consistently released exams many months after a product launches. Although I may be wrong, I wouldn't expect to see .Net exams and a new track until spring of next year at the earliest. Also, the .Net exams will probably be quite different from the exams available today. For one, the technology is drastically different. In addition to that, Microsoft is making a conscious effort to make the exams more difficult (like the Solutions Architecture exam). Personally, I would highly consider leveraging the knowledge you have today, and get your MCSD now.
This was first published in February 2001