VMware have their own FAQ page for their certifications, but I get emails and have conversations with people all the time who ask me questions like the ones below - so I thought I'd share them with you here...
If I haven't answered your question here, you can always email me at firstname.lastname@example.org
1. Can I self-study for VCP?
People often ask me if they can self-study for the exam/certification - well anyone that knows the VCP program will tell you "No" - VCP has always had a training requirement for first-time achievers.
For VCP5, you can take a number of different vSphere 5 training classes, here's the reference page for that: http://www.vmware.com/go/vcp
Once you achieve your first VCP, there is always an "upgrade" path to the VCP on the next vSphere release - for a limited time (normally 6 months) you can just pass the new exam and that gains you the new VCP.
2. Do I have to do the training before the exam?
No, it is not essential to take the training first, although it is recommended.
3. How long can I leave between the training and the exam?
Technically you can leave as long a gap as you want - the only deadline is the future availability of the training and the exam for that version. So for VCP5, as long as you can get trained on one of the qualifying vSphere 5 classes and the VCP510 exam is available to take, you can achieve VCP5.
It gets harder to find training on an older version once a new version is released, and the exam for the old version will be retired eventually.
4. Does my VCP expire?
This is a simple one - no it does not. VCP certifications are version-specific, they stay with you forever - at the time of writing I'm a VCP2, VCP3, VCP4, VCP5 and I always will be.
If you want to stay current when a new vSphere version comes out, you will of course need to meet the VCP requirements for that new version.
5. What vSphere versions hold a VCP certification?
VCP certifications relate to the major version only, so when I say I'm a VCP3 that means my VCP applies to all the 3.x versions. The exams are normally generic across a major version, so you will be asked questions in the VCP510 exam that have answers applicable to all vSphere 5.x versions.
UPDATE: VMware have now released an exam specific to vSphere 5.5 - the VCP550 exam - passing this exam or the VCP510 exam (agnostic across vSphere 5.0/5.1) will gain the VCP5-DCV certification for those who have also met the training requirement.