I finally made good on my promise in part I, so here’s part II.
Via this interview with Philip Emeagwali (left) and this article by Assante Darko (Right) of the University of Lesotho, we further explore the African Diaspora question and all it’s ramifications.

The African Diaspora conundrum could either be interpreted as “brain drain” or “brain gain” depending on your convictions on the subject matter. I believe my sanguine introduction in part I casts me in the glass-is-half-full camp. So be it. 
The “brain drain” theory says: Skilled Africans migrate to foreign countries with their ICT skills, and in essence, depleting the residual skill/academic pool while enriching their destination countries with same. In the SSA context, the “Brain drain” theory resonates pretty strongly with the Atlantic slave trade theme – where SSA suffered a massive drain/depletion of “prime” economic capital (read: human capital). The associated trepidation with the “Brain Drain” point of view is not totally baseless per my paraphrased version of this libertine theory on wealth: 

“ If you took all the trained, skillful, and accomplished sub-Saharan Africans and moved them to a deserted Island with only the clothes on their backs, leaving behind all their material wealth and acquisitions. In 10 years, Sub-Saharan Africans will still be wallowing in the throes of HIV/AIDS, begging for UN handouts and IMF bailouts. While on the desert island congress floors, they’ll be arguing aid and support package propositions for Africa as well as curbing illegal African immigration to their desert Island.”  

This is no trickle-down economics jingoism. The point I'm making is that the economic progress of society is driven by the skilled, trained and accomplished citizens.

The “Brain Gain” theory however runs circles around the biggest phobia of the “Brain Drain” theory;  that Diaspora is equivalent to lost skills totally unusable to sub-Saharan African societies.
The “Brain Gain” theory is a more contemporary spin on the greater Diaspora subject matter, which basically purports that: Diaspora is essentially a vehicle to enable sub-Saharan Africans acquire training and skills from elsewhere and then turn around and plough it back into sub-Saharan Africa, thus enriching the continent. The “Brain Gain” theory of course, thrives on recent globalization trends, that is; societies are becoming more networked and the world is becoming a super-sized village square. Hence via the omnipotent munificence of the World-Wide Web, sub-Saharan African émigrés can cheaply and conveniently email, chat, make phone calls back home – connecting with the motherland almost like they never really left home at all. Ample evidence abound to support this overwhelmingly digital-flavored thrust of the “Brain Gain” theory in the UN report on fund remittances and investments by African Diaspora (about $20 Billion per Annum), as well as our “doing business in Africa” heroines; Enonchong, Maddy, and a whole lot more of us out there in Diasporaville!
The “Brain Gain” theory largely gained traction in tandem with the rising prominence of the World-Wide Web, their DNAs are inseparable genetic fiddle-faddle; case in point to demonstrate this "Brain gain" and WWW relationship premise is India. Prior to the presently celebrated Indian IT boom ushered in by the WIPRO-IBM-Microsoft-et al invasion of Bangalore, there was a burgeoning, world standard, specialized medical practice industry of India – Westerners/Americans were (still are) flocking to India for cheap/affordable organ transplant surgeries, super-complex maxillofacials, cosmetic surgeries, the whole gamut! And all that cacophonous din of clanging oxygen tanks and body-strapped dialysis paraphernalia heading towards India was an ant peep compared to their latter IT revolution. Where the medical practice signaled a great economic stride for India, it was still a comparatively small market, hardly of global proportions  because the Indian medical skills employed therein were locked into a simple "reverse-the-brain-drain" mode; go, learn the skills, come back and apply it at home. The IT revolution however, has seen Indian skills, brains and voices criss-crossing the entire google-fied planet in mind-boggling volume and breadth of vocations -- a giant bi-directional knowledge multiplexing framework, with the huge brain-gain (as well as economic) dividends trebling and quadrupling in astronomic swells. Point is, "Brain Drain" and "Brain Gain" may not necessarily be opposing theories, the former can be transformed into the latter via catalyzing factors such as information and communication technologies (ICT).