In a medium saucepan combine milk, split vanilla bean, and salt. Bring to simmering. Cover and remove from heat. Let stand for 15 minutes to allow vanilla bean to infuse milk with its flavor. Remove vanilla bean; set aside.
Bring milk mixture just to boiling over medium-high heat; reduce heat to medium. Gradually add polenta mix, stirring constantly. Cook and stir for 5 to 7 minutes or until mixture is very thick. Remove from heat. Stir in sugar. Let stand, covered, for 5 minutes.
Meanwhile, in a small bowl combine mascarpone cheese and honey. Using the tip of a small sharp knife, scrape out seeds from vanilla bean. Discard pod or reserve for another use. Stir vanilla seeds into mascarpone mixture.
To serve, divide polenta mixture among six dessert dishes. Top with preserves and mascarpone mixture. Serve warm.