Doing some additional "googling", I've found some recent articles with interesting tidbits about the upcoming service...

"free service for frequent fliers was among its options"
-CNN

"The airline isn’t looking at the satellite-based Internet service so much as a source of additional direct revenue for the airline, but rather as a way to differentiate the airline’s service from that of its rivals, he said.

“We haven’t penciled in any revenue in future budgets. I think it’s a use of technology for a better customer experience,” Jarvis said.

Alaska could become the first U.S. airline to equip its whole fleet for Internet service if its spring test flights prove the service technically feasible. It expects to have all of its planes equipped by the end of 2009"
-The News Tribune

"Alaska Airlines plans to run a month-long test of Row 44’s satellite-based system on its Boeing 737 aircraft this spring, and if the results are satisfactory, Alaska Airlines will equip all of its 114 airplanes with Row 44’s service."
-PC Today