From what I know, and it is not too much but is a lot more than in 2004, a lot of that answer depends on the organization and their views. Our son was a 25th round pick and his contract says he was headed to a "Rookie" league. After a mini-camp, he ended up in short season A, got some chances there and survived and got another chance in low A and survived. I also know of a 2005 free agent(undrafted college senior) who was assigned to Rookie ball last summer and now has really created some interest.
In the minor leagues, you come to hear the term "organizational" player. When you read that in a scouting report or hear it from a scout, that is the player you are describing. Some organizations let you earn more, some may not.