Clustering itself is not a bad thing - but like many things, it can be misused. The biggest problem I see is when customers think clustering is what they need, when what they really need are more attentive and knowledgeable exchange administrators who actually monitor the servers and hardware.
Not being an Exchange admin, I had no idea what that in-joke is all about. Thankfully Google Groups is there to explain to those sitting on the client-side...
