According to VMware knowledge base article 1317898 it is not possible to reset the root password of an ESXi installation. Well, maybe it's not easy for non-Unix guys, but it certainly is possible.
In VMware ESXi, the SNMP query interface is not included. If you want to monitor your VMware hosts, you either have to buy ESX, or you have to wrap your solution around the VMware CLI tools.
I recenty watched Dan Walsh's presentation at Red Hat Summit on SVirt. Here' what I took away from it, including some additional thoughts and explanations from myself.
I have a server that has an AMCC 3ware 9650SE RAID controller for all its disks. For this controller, a 3rd party driver for VMware ESX 4.0 is available. It is not contained on the default installation disk of VMware.