Using the HTC developer phone the update to Android 1.6 will most probably the last one you can run on this device. Version 2.0 will not run on it (officially)
To update the version from 1.5 to 1.6 you follow the same steps as in my previous blog entry about Android update (link) using the lastest files from HTC (link):
- Radio Image: ota-radio-2_22_19_26I.zip (same file as for 1.5)
- Recovery Image: signed-dream_devphone_userdebug-ota-14721.zip
The release notes of 1.6 (from September 2009) you find at android.com.
If you dare to walk outside the standard path, go to Cyanogen.com for a homebew, but popular mod.