IBM hasn't left yet https://www.valuewalk.com/2013/05/research-in-motion-ltd-bbry-boom-on-ibm-takeover-talk/
If the recovery is proven on track by the Q1 in June, then whenever IBM plans to move ahead, $60 could be a big steal, anything below will be a joke.
Check the techology background for both of them you could find out so many key services/product can be integrated in common extending IBM's reach in the real mobile world, esp in business solutions. A perfect match they can think of.