Businessman, BlackBerry and BBm

RIM's blackberry in the visual culture view has long held the dominant View as the smartphone choice of businessmen, however BlackBerry over the past year has been slowly losing ground in the smartphone market. Why is this? What role has RIM's inability to substantiate and expand on its mobile App platform had in its demise of market share? And where does BlackBerry look to stand in the larger smartphone consumption communities of practice?

.... [ note this blog post is a though, the research into these questions has not fully been completed ]