It is a big risk for 8ta but I think it will pay off in thousands of ways:
(1) 8ta needs to get enterprise clients, having some BB clout accompanied with their closed user group accounts makes this possible. Now this product should get 8ta lots of BB customers (yes they may be low spend consumers) and should enable them to both negotiate with BB and to convince enterprise clients for whom BB enterprise isn't what they want instead simply needing consumer BB to join up with 8ta.
(2) Whilst a lot of BB users are "low spend" on voice et al a lot of BB bunnies are stupid fad following twits. The sort of twits who spend R50 to have nonsense sent to their phones. Getting a lot of these teenagers to go over to 8ta gives 8ta the ability to (a) derive revenue from this spend and (b) ensure that all the little vampires who deliver these services join onto the 8ta ship.
(3) BB is still "cool" in SA. Whether BB dies or caves into opening itself onto Android systems is still to be seen. The point is that been linked to BB is good for marketing all round.
(4) Being at the forefront of cheap communications makes 8ta a poster child for social improvement through technology.
Personally I don't believe that RIM is dead or even dying, they are at the stage in technology companies cycle of needing to weather decline and build into the next round of existence. I suspect that a large part of RIMs future lies in becoming a SaaS provider in the enterprise mobile applications field and that we will see them bringing out a range of Android apps and VPN orientated server systems for medium sized enterprises.