Too much doom and gloom here. I don't have the impression that BB will leave within 3-5 years. Too many government contracts for cell-phones and software contracts in lots of different fields to be gone that quick.
Never understood the hate BB gets. I already had positive experiences with QNX and I think it was a very good move from BB to use that as base for BB10.
The only reason I own a Lumia is because I don't want to tinker around with sub-par computing devices that happen to be able to make a call (Android)...or continuously fight with the school yard bully over my lunch money (iOS).
Both BB10 and Windows Phone have a much more business like appearance and their devices are good for making calls. Exactly what my phone needs to do. Couldn't care less about facebook, whatsapp or games on such a tiny device. Sub-par experience on sub-par computing devices is the best you can hope for and most of the time you don't get even that.
While saving for a BB Z10 (yep, people still do that...and I wanted a phone without contract and that makes phones quite expensive here in Paraguay), someone offered me a Lumia cheaply. Never regretted that moment as it has already have a lot of functional stuff in it that doesn't require a internet connection and I can use all that directly from my desktop PC if I want to.
All I want to point out is that the way you want to use your smart phone is definitely not how I want to use mine. Which in turn will make us both look for very different qualities in our phones. If BB wants to cater for people that prefer a more business/no-nonsense like experience...let them. It is/was their core strength to begin with and it served them well.
Smart phones should be regarded as slave devices (fill in the "slave" part how you will), all of them suck as a device to control other devices and you are nickel-and-dimed continuously for that experience. Not worth my time, money or energy, I'll rather use that productively.
More on-topic now: the website 'crackberry' posted a decent piece
about hands-on experience with the Passport and the reviewer was positive about almost all qualities of the device, but also stating there are things to get used to before you appreciate the workflow BB envisioned with this particular phone.
The passport is probably not your cup-of-tea, I can tell you with certainty that its look hasn't won me over. But as far as I understand, its greatest disadvantage will be the introduction price (without contract).