Following are some resources referred to during the discussion, afterward in one-on-one chats, plus a few that I thought might be of interest for futher reading. As the panel turned out to be, these are mostly technical, with a few of interest to analyst types. I too wish that we had a bit more coverage of business case studies.
[Big Data: Principles and best practices of scalable realtime data systems][marz]
Nathan Marz and James Warren (Manning Publications)
A wealth of insight on building an architecture employing multiple data stores in order to serve differing latency requirements, and hedge risks and weaknesses. Marz initially developed Apache Storm for Backtype, acquired by Twitter. Still in "Early Access Edition" status, but all chapters are now available. If you're not technical but you'd like an introduction to the technical considerations, [Marz's post that led to the book][marz cap] is a briefer overview.