What can I do with it?
Delete an event from the current session. Note: to unsubscribe from an event you will need to use Unregister-Event.
Get-Event Remove-Event -SourceIdentifier Timer Get-Event
You will see that the event has been cleared.
How could I have done this in PowerShell 1.0?
PowerShell engine events are a new feature in PowerShell 2.0.