1. A method for resource allocation in a virtualized computing environment comprising at least one physical computing system hosting multiple virtual machines, the method comprising: dynamically allocating physical computing resources of the at least one physical computing system amongst the multiple virtual machines, each virtual machine configured to execute a virtual desktop that is remotely accessible by a user, the dynamic allocation including: receiving indications of importance corresponding to activities triggered by an active user session with the virtual desktop that can occur on the multiple virtual machines; monitoring a state of the virtual desktop of each virtual machine to detect the activities triggered by the active user session; determining, based on the monitoring of the state of the virtual desktop, that one of the activities has been triggered by the active user session and is occurring on one of the multiple virtual machines; and in response to the occurring activity, automatically modifying, based on the occurring activity and its corresponding importance, an allocation of physical computing resources of the at least one physical computing system that are assigned to the one virtual machine.