As College Park continues its transformation with new housing, retail and other businesses, its latest upscale eatery is primed to make its mark. GrillMarX Steakhouse and Raw Bar opens today in the space previously occupied by the Old Maryland Grill in The Hotel at the University of Maryland. The elegant yet casual restaurant, which also has locations in Olney and Columbia, is known for its hand-cut steaks, as well as seafood, salads, sandwiches and cocktails. It is the latest addition to the Greater College Park initiative, a $2 billion public-private partnership that aims to place the community among the nation’s best college towns.