RIM has been adding new subscribers to its BlackBerry service at a faster-than-normal rate in recent months. This rapid expansion may have contributed to the crash. RIM had better move fast to take care of this and to make sure it doesn't happen again. If BlackBerry has any competitive advantage against the likes of Nokia, et al, it's the service's sterling reputation as a bulletproof system that just works. Outages like this tarnish the BlackBerry brand and open new opportunities for RIM's competition.
If I were Nokia, Motorola, or Microsoft, I'd be marketing the heck out of this BlackBerry outage. Now, can any of RIM's competitors actually capitalize on this?