In case you missed it, this tweet floated across the Twitters last week:
Yes, the team at Arc2Earth is apparently working on a new feature in Arc2Earth Sync, called TileMill Connect, that will link ArcMap MXDs with TileMill. This will allow users to migrate their ArcMap cartography into TileMill to take advantage of the rich tools there as well as the potential for version control and cut/paste sharing of techniques and best practices enabled by CartoCSS.
Brian Flood followed that up today with a short video showing it in action.
No word on a timetable for this feature, but I can’t wait to kick the tires. I am especially intrigued by the pseudo PostGIS proxy service that enables connections to ArcGIS data sources.