HTC Desire root is now available for download which gives you full file (root) access on your Android 2.1.
Paul from Modaco forums has also posted some details on the limitations of this root and has also posted instructions and requirements to perform this on your HTC Desire.
HTC Desire root is out and it will be using a 10MB installation of Linux called as Tiny Core. HTC Desire and HTC Legend root news was out a couple of months back when Paul from Modaco forums was able to root both the devices.
Rooting HTC Desire was not as easy as it used to be in the times of HTC Hero and other devices. But he finally managed to pull the root for HTC Desire. HTC Legend root will be coming soon.