There was a question today on the VMTN forums about obtaining the latest version of resxtop for vMA to utilize the new NFS datastore counters. Unfortunately, there is no automatic method of updating vMA to get the new version of resxtop, which is part of the vCLI 4.0 Update 2 package. The current release of vMA 4.0 contains the GA release of vCLI 4.0 (May 2009). VMware has since released both and Update 1 and Update 2 of vCLI.

You will need to copy the tarball to your vMA host using either UNIX/Linux scp command or WinSCP if you're on a Windows system. Once the package has been uploaded, you will login to your vMA host and you should see the package in the current working directory:
[vi-admin@kate ~]$ ls
VMware-vSphere-CLI-4.0.0-253290.x86_64.tar.gz
Now you will extract the contents of the tarball using the following command:

[vi-admin@kate ~]$ tar -zxvf VMware-vSphere-CLI-4.0.0-253290.x86_64.tar.gz
After extracting the contents, you should now have a new folder called vmware-vsphere-cli-distrib:

[vi-admin@kate ~]$ ls -l
total 18304
-rw-r--r-- 1 vi-admin root 18714362 Jun 28 10:35 VMware-vSphere-CLI-4.0.0-253290.x86_64.tar.gz
drwxr-xr-x 10 vi-admin root 4096 Apr 23 01:01 vmware-vsphere-cli-distrib
You will now cd into the vmware-vsphere-cli-distrib directory and run the installer. The first time you run this, you will get an error and you need to remove the installer db at this time to proceed with the installation:

[vi-admin@kate vmware-vsphere-cli-distrib]$ sudo ./vmware-install.pl
A previous installation of vSphere CLI has been detected.

Uninstallation of previous install failed. Would you like to remove the install
DB? [no] yes

Removing installer DB, please re-run the installer.
Note: (This is necessary since the installer script does not support a clean upgrade from what I can tell)

Once you have successfully removed the installer db, you will need re-run the previous command which will start the installation (accept all the defaults and ensure you do overwrite the utilities):

[vi-admin@kate vmware-vsphere-cli-distrib]$ sudo ./vmware-install.pl

......

The installation of vSphere CLI 4.0.0 build-253290 for Linux completed
successfully. You can decide to remove this software from your system at any
time by invoking the following command:
"/usr/bin/vmware-uninstall-vSphere-CLI.pl".

This installer has successfully installed both vSphere CLI and the vSphere SDK
for Perl.

Enjoy,

--the VMware team
After this, you now have the latest version of vCLI 4.0 Update 2 installed on your vMA host.

The biggest feature with this new release of the vCLI is the NFS datastore metrics which has been a sought after for awhile. One other feature that has not gotten too much attention in the new version of esxtop/resxtop is the power management metrics, denoted by the new "y" option.