Despite slow sales growth over the past three months, the iPhone is still fresh in the minds of most smartphone users. So fresh that a lot of them wish they owned Apple’s handset instead of their own. A new study from market research firm Crowd Science shows that 40 percent of Blackberry users will be switching to an iPhone when their current plans are up.

It’s not just the iPhone. Some 32 percent of Blackberry users said they would switch out for a Nexus One when the time came. The real trouble, it seems, is RIM’s platform. While Android and Apple’s iPhone OS have matured into serious entertainment platforms, RIM has tried to rally a stalwart defense of its corporate clientele. Oddly enough, that defense has looked like offering more of the same that made the Blackberry a success in a pre-iPhone world.

It’s already too late for RIM to turn this ship around. The company needs a new operating system and a completely different pitch, neither of which are likely to happen in the next six months. By then the defectors will really start to hurt. Don’t bet on Android or iPhone users heading RIM’s direction, either. Some 90 percent of those users plan to stick with their current platform.