The short version is that it appears the goal is to boost density near the Rockville Metro and Twinbrook Metro Stations. The center of the pike will probably remain low density because there is a lack of (road) transportation due to the Country Club. The other major improvement is to turn the pike into a Boulevard (
http://en.wikipedia.org/wiki/Boulevard#United_States_and_Canada) with access roads to the side to improve traffic flow.
The plan is better than what is there but will not immediately provide the high densities required for proper mass transit.
Right now the road is a very long suburban strip mall with some office complexes. The result with be more mixed use development.
The downside is that improving traffic flow will simply put off the day when we get metro expansion (in Rockville), light rail lines and trolleybuses to feed the metro system.
Somthing is better than nothing.