Research In Motion (RIM) has been fending off competitors in its enterprise segment while trying to tap the consumer market, and if analysts’ predictions hold true, those efforts appear to be working.

The BlackBerry maker will be reporting its second-quarter results after the market closes today. It’s expected that its earnings will grow 15 percent over last year, hitting $1 per share on sales of $3.62 billion this quarter.

“Research In Motion is still going to be the dominant player, but they’re going to see a lot of pressure from competition and they’ve got to step up their game – and they’ve started to,” says Frost & Sullivan analyst James Brehm.

Sales of the BlackBerry Tour, released in July, seem to have been strong despite initial problems with the smartphone’s trackball. RIM’s latest software update for the device seems to be targeted at the consumer segment with easier Web browsing and the incorporation of more user-friendly widgets into the home screen.

However, the company’s massive market share in the enterprise segment is vulnerable to encroachment by the likes of the Palm Pre and Apple’s iPhone. “When you’ve got over 60 percent of the market, you have no where to go but down,” says Brehm.

That’s not to say losing market share is a bad thing – Brehm says that the rapid increase of RIM’s device shipments will offset any decline in the company’s market share.