I don't think it's ever too late in a tech market as long as your company still has enough funds to launch and market one more product. After all, if you'd looked at pre-iEverything Apple a few years ago and claimed they would be the most valuable company in the world today, most people would have laughed.
That said, RIM clearly has an uphill struggle ahead of it. They need a smash hit, which means they need people with vision at the top. They have limited funds for repeated attempts, so unlike the Microsofts and Googles of this world they can't afford to keep throwing stuff at the wall until they find something that sticks. They've had a string of PR and management disasters in recent years, which matters far more to a business-based market than to consumers. And with the likes of Apple, Google, Microsoft and Amazon all now heavily invested in mobile technology and competing for most of the biggest market segments, it's going to be tough to find a niche that is small enough to make a defensible foothold and yet big enough to expand out into a serious player again.
My guess is that they need a new kind of device, some novel form factor or combination of features that creates or brings credibility to a whole new market the way Apple has done more than once. There are pain points with a lot of the current generation mobile devices, and in particular those devices that rely mostly or entirely on a touchscreen are always going to be primarily consumption devices, which means mobile content creation is an area with potential. RIM actually has a very good track record of, for example, combining real keys (albeit mini ones) with great displays (before the turkey that was the Torch, the half-height displays at the top of high-end Blackberry phones were pushing the resolution frontier long before Retina came along).
Another possibility, and one that is not mutually exclusive with the above, is that RIM could aim for a clean, professional, businesslike UI. Not everyone wants Facebook integration and iFart apps. Personally I don't even want those on my personal phone, and I certainly have no interest in having them in my business devices. On the other hand, I would love to have some mobile gear that started with basically nothing preinstalled except for an OS and comms tools, that had tools available to interoperate with whatever grown-up systems I want to in an easy and secure way, and that had an "app store" with professional software that did useful things. If the same organisation supplying that mobile gear also happens to provide useful back office products and native and/or web-based interfaces that let me talk to them from my desktop/laptop/other large-scale devices, so much the better. Again, RIM probably have more talent in-house in this sort of area than a lot of companies, if they can figure out how to harness it.
Oh, and if RIMM shares are at $500 in five years because they've cornered the "in-house cloud" market, someone please let me know so I can tell them where to send the cheque. ;-)