The base QNX operating system is intriguing and efficient. I like the fact that they made a tiny nano-kernel operating system focused on what mobil devices need to do. But I'm not sure that efficiency and innovation alone will be enough to save them.
IOS and Android, even though slightly inefficient in comparison to QNX, are still highly functional. And since most users only change platforms because of improved functionality (and not efficiency), it'll be hard for BlackBerry to lure any converts over to its device.
I would not be investing in BlackBerry right now, unless I thought Apple or Google were going to buy them just to own QNX.