Not sure if anyone has noticed, but sometime recently Southwest / Marriott increased the number of Marriott points is takes to get Southwest points. Below is the new conversion tables. You can find this on the Southwest Airlines web page under Rapid Rewards, Partners, Travel Marriott Learn more.

You can also redeem your Marriott RewardsŪ points for Rapid Rewards Points.
10,000 Marriott Rewards Points = 2,000 Rapid Rewards Points
20,000 Marriott Rewards Points = 5,000 Rapid Rewards Points
30,000 Marriott Rewards Points = 10,000 Rapid Rewards Points
70,000 Marriott Rewards Points = 25,000 Rapid Rewards Points
140,000 Marriott Rewards Points = 50,000 Rapid Rewards Points