The new operating system promises better multitasking than either the iPhone or Android. Simply swipe a finger across the phone's display screen to switch to another program.
All emails and notifications from such applications as Twitter and Facebook go to the BlackBerry Hub, a nerve center accessible with a finger swipe even if you have another application open. One can peek into it and open an email, or return to the previous application without opening the email.
"You are not going in and out of applications; you're flowing through applications with one simple gesture of your finger," Costanzo said. "You can leave applications running. You can effortlessly flow between them. So that's completely unique to us."
That said, multitasking will still be limited. If you're watching a video, it will still run while you check for email. But it will pause if you decide to open an email and resume when you are done.
The BlackBerry's touch-screen keyboard promises to learn a user's writing style and suggest words and phrases to complete, going beyond typo corrections offered by rivals. See the one you want, and flick it up to the message area. Costanzo said that "BlackBerry offers the best keyboard, period."
Gus Papageorgiou, a Scotiabank financial analyst who has tried it out, agreed with that assessment and said the keyboard even learns and adjusts to your thumb placements.
The first BlackBerry 10 phone will have only a touch screen. RIM has said it will release a version with a physical keyboard soon after that. That's an area RIM has excelled at, and it's one reason many BlackBerry users have remained loyal despite temptations to switch.
Another distinguishing feature will be the BlackBerry Balance, which allows two personas on the same device. Businesses can keep their data secure without forcing employees to get a second device for personal use. For instance, IT managers can prevent personal apps from running inside corporate firewalls, but those managers won't have access to personal data on the device.
With Balance, "you can just switch from work to personal mode," Papageorgiou said. "I think that is something that will attract a lot of people."
RIM is also claiming that the BlackBerry 10's browser will be speedy, even faster than browsers for laptop and desktop computers. According to Papageorgiou, early, independent tests between the BlackBerry 10 and the iPhone support that claim.
Regardless of BlackBerry 10's advances, though, the new system will face a key shortcoming: It won't have as many apps written by outside companies and individuals as the iPhone and Android. RIM has said it plans to launch BlackBerry 10 with more than 70,000 apps, including those developed for RIM's PlayBook tablet, first released in 2011. Even so, that's just a tenth of what the iPhone and Android offer. Papageorgiou said the initial group will include the most popular ones such as Twitter and Facebook. But RIM will have to persuade others to make a BlackBerry version, when they are already struggling to keep up with both the iPhone and Android.
Like many analysts, Papageorgiou recently upgraded RIM's stock, but cautioned that longtime BlackBerry users will have to get used to a whole new operating system.
He said RIM can be successful if about a third of current subscribers upgrade and if the company can get 4 million new users overseas, especially in countries where the BlackBerry has remained popular. IDC said smartphone shipments grew 44 percent in 2012. If those trends continue, it will be possible for the BlackBerry to grow even if iPhone and Android users don't switch.
"This doesn't have to be the best smartphone on the planet to be a success for RIM," he said. "I think the big question though is, if it fails, is it just too late? Are the other two ecosystems just so advanced that no one can catch up? That's a big risk."
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