Status.marriott.com (updated 8/28) states:
- Transferring Points to Airline Miles: There is a temporary limitation on the number of points a member can convert to miles. Members can transfer up to 80K points to airline miles per day. This limit will be increased to a new daily threshold of 240K in the coming weeks.
But fails to mention that for many airlines it doesn't work. The 80K cap is fine for me - I just need the transfer to Alaska to work!