Each week brings more discouraging news about Research In Motion, the Canadian-based BlackBerry owner. Today, the company is dealing with Apple’s recent introduction of its iMessage service and how it is already affecting its own BlackBerry Messenger product. The news isn’t good, according to TechRadar.

RIM’s investors are so unhappy about Apple’s announcement they have pushed RIM’s stock to a four-year low. On Tuesday alone, the day after the Apple announcement, the stock tumbled 3 percent. Today it is down nearly 2 percent.

The reason for concern is that until Monday, BlackBerry Messenger was the only IM service of its kind and “had proven very popular with the teenage market.”

According to TechRadar:

Rumours that BlackBerry would release and iOS and Android Messenger app have so far come to nought, but RIM could yet claw back kudos by opening BBM up so that Apple, Android and BlackBerry users could all IM each other… that’s a utopian dream we can’t see coming to pass though, if we’re honest. [sic]

Of course, RIM doesn’t just have to deal with Apple. Google’s Android is also hurting the BlackBerry owner.

In April we reported just 11 percent of future handset buyers would chose a BlackBerry, versus 31 percent for an Android-based device, and 30 percent who indicated they’d buy an iPhone.

Just last week we asked whether Apple’s iCloud service would eventually kill off BlackBerry.

What do you think? Are BlackBerry’s days numbered, especially with the introduction of iMessage? Let us know by using the comments below.