Not a promising development. This announcement came way back in JANUARY, when McCain was not the leading Republican candidate yet--facing off against more conservative Republicans. Schwarzkopf could have very easily tipped the races, especially with the military vote, by endorsing Romney, who would have been enormously better. Instead, he went out of the way to endorse the most leftist of the Republicans--and the weakest candidate.
The fact that Schwarzkopf has not endorsed McCain, or spoken out for him, lately tells me he is likely not on board with him. If he were really in the McCain camp, he'd be campaigning now. Most of the people who are endorsing Obama now endorsed McCain in the primaries. I would not be surprised to see Schwarzkopf join the endless legions of schvartze-worshippers now.