Previously, the FTA relied heavily on “travel time savings” to judge the merits of a project. The new formula will focus instead on the number of passengers expected to be served. Economic benefits like the impact on development will also be considered.
Basically the old formula encouraged park-n-ride projects with long spaces between few stops in order to keep the speed high. Those aren't the kinds of projects urbanist transit nerds like very much, as they aren't complementary with walkable development.