I found an interesting article here by Stephen Garrison on TopTech News dealing with the enterprise networking needs of mid-sized companies.
His take is that switch performance is never something to skimp on, with high-performance, line-rate throughput on all ports a must. The overall architecture should provide non-blocking, low-latency switching even under full data loads.
In fact, Garrison says the best way for mid-sized companies to gauge their network needs is to take a look at what the larger firms need. Network requirements are generally the same, although on a slightly smaller scale. And right now, the trend in large-scale enterprises is multiple hundreds of GbE interfaces tied to modular 10 GbE interfaces so you can scale up trunking and core uplinks as needed.
High densities in small form factors also go a long way toward simplifying network infrastructures even while cutting you a break on power and cooling requirements.