The vSphere Configuration Maximums constantly come up in VMTN discussions about the VCP5 exam. Many people report that they received no configuration maximum questions on their VCP5 exam, but I don't think that this is entirely true. I think what people are implying is that they didn't receive any of the old VCP3-style questions that just centered around knowing a specific configuration maximum value. The exam has evolved and so have the questions.
I would venture to bet that nearly every one that takes the VCP5 will receive questions where knowing values from the configuration maximums will be required to answer the question. I know that when I took the VCP5 BETA, there were many questions that required knowledge of configuration maximums. The questions were not the simple "how many X are supported" type questions, but more involved questions where you couldn't arrive at the correct answer without knowing a value from the configuration maximums.
Objective 4.3 of the VCP5 exam blueprint lists the required knowledge of "Identify the vCenter Server managed ESXi hosts and Virtual Machine maximums." This objective guarantees that configuration maximums are included in the VCP5 exam. My advice is to not let anyone else's exam experience sway you into thinking that you do not need to know the configuration maximums for the VCP5 exam. Also remember this: Knowing the configuration maximums could be the difference between passing the VCP5 or not. It would definitely be better to spend some time with this document, before you take the VCP5 exam.