I don't give much to Windows OS taking over as the top mobile OS. Even after teaming up with a mobile giant (Nokia) they are still slow to make any grounds on catching up to the big two (iOS and Android). Plus there tablets are expensive and confusing (can anyone tell me the difference between Windows RT and Windows 8?). Consumers hate confusion (look at all the questions regarding software versions and hardware on this forum). Nokia would have made a killing by producing an Android powered phone (idiots).
I am willing to give RIM a chance despite there horrible attempt to get into the touchscreen section of smartphones. RIM is that zombie that just won't die. They have a very loyal following and even though they lost a lot of shares from the business world (iOS mainly taking some of that away, Android a bit) there are still tons of companies using BB. There chance (a rare one at that) is fast approaching with the planned January 30th event. I believe this will be there last chance to make a come back. To do so they will have to release a polished, intuitive, fun but serious at the same time operating system. They will also need to provide firm dates on January 30th of when the hardware will be available. If they leave the consumers guessing there won't be much of a following. My 2 cents anyway.
So I give it to RIM and BB10 to make a dent in the mobile OS wars. In no way will they topple either iOS or Android, but they definitely have a chance to bring in the numbers.
Past Devices: Google Nexus One (sold), Samsung Galaxy S2 (sold), B&N Nook (returned), Samsung Galaxy Tab 7 (sold), Samsung Galaxy Tab 10.1 (On the Shelf)
Current Devices: Samsung Galaxy S3 (AOKP), Nexus 7 (Stock), Chromecast