VMware has released a draft of the vSphere Hardening Guide, and are encouraging feedback from the community.  It is broken into multiple pieces.
Part 1: Introduction
Part 2: Virtual Machines
Part 3: Host
Part 4: vNetwork
Part 5: vCenter
Part 6: COS

Simon Long of The Slog has posted a VCP vSphere Practise Exam built out of VMware documentation and personal information and experience.  Looks great, I plan on taking it tonight to brush up!
Take the Exam here.
VCP vSphere Practise Exam

Duncan Epping of Yellow-Bricks.com posted an article reflecting on another year passing by in his life; however the the article turned into much more with great insight and information on how and why he blogs with tips for others looking to make the dive into it themselves.
I personally have taken (stolen with credit given, but [...]

Congratulations to all those that won, and those that placed.  Many great vendors with fantastic software in this list!  Take a look at each of them for your own VMware infrastructure, they can add a great deal of value.
Old hats to VMware like Vizioncore with their vRanger are still top of their game, and newcomers [...]

VMware document defining Scheduler process improvements, and changes for ESX 4.  There are some very significant changes, and there are always many customer, client, and user questions about how ESX handles the Scheduler functions.
Get the document here.

If you are like me and get lots of questions about something that most customers, users, and even administrators will never see or interact with but is very core to Virtualization; this is a great 4 point list for you from Drummonds of VMware.
Check out his post here.

Within ESX 4 the /ui/ website has been disabled by default.

There is still a disconnect between the DPM (Distributed Power Management) and VUM (VMware Update Manager) products.