It seems like every time Research in Motion takes half a step forward something comes along to knock them a full step back.  In this week’s edition of What Else Can Go Wrong for RIM, energy services company Halliburton has announced plans to drop support for BlackBerry in favor of the iPhone.

“We are making this transition in order to better support our mobile applications initiatives,” said Beverly Blohm Stafford, director of corporate affairs for Halliburton, in a statement. “Halliburton has engaged with Apple on this transition.”

Of Halliburton’s 70,000 global workers, 4500 of them have been issued BlackBerry devices which will be swapped out for iPhones over the next two years.  Companies, in increasing numbers, are allowing employees to connect their personal iPhones to corporate email systems.  If Halliburton follows suit, the number of iPhone users they support could number in the tens of thousands.

[Via New York Times]