Where is TRILL and Why Stacks are Awesome?
While it definitely commonplace to collapse the Core and Distribution layers where feasible and practical, I don't understand how one could have any discussion of a large, flat network without a mention of TRILL. Given the love lost over Spanning-Tree Protocol and the subsequent need for Layer 3 routing to segment STP, TRILL provides the defacto hope of collapsing large, distributed networks into a wide, flat topology that can be as interconnected and filled with loops as needed. Especially now, TRILL should be the first feature requirement for any Ethernet switch hardware selection process. Admins the world over will rejoice when they can execute "no spanning-tree" on all the switches.
Regarding stacking switches, there is a flip-side not mentioned by the author in the switch stack argument. The assumption not plainly stated, but inherent to the logic provided, largely holds that the campus network is managed in-house. Generally, if the stack will be managed by a third-party, that third-party will still charge on a physical chassis basis, not per logical device. So, it pays to understand the ramifications of such "simple" choices on the bottom line (or any of the other myriad areas of impact within IT beyond purely financial). There's also a need to evaluate vendor claims about stacking, as not all implementations may be equal (such as Cisco's StackWise or VSS).