As an owner of an HTC Dream, I can confirm that this does indeed work! Cyanogen's website has been updated to include the new method, using the DroidX method:
Here is the procedure to install CM 5 on Windows:
Before we do this, here's the generic legal: This WILL erase everything on your phone, so backup backupbackup. If the phone does brick, though extremely unlikely if you follow it step by step, myself, AndroidHeadlines, ezterry, XDA, or anyone else besides yourself are not responsible. So be careful!
1) Download the following files:
DroidX Root (Need to register in their forums)
Amon Ra's Dream Recovery v1.7.0
CyanogenMod EB1 kernel
Google Apps Addon for CyanogenMod
(If you don't have it already) Android SDK, for FASTBOOT and ADB
2) Extract the android SDK to a convenient location. Enter the Tools directory.
3) Move all other downloaded files above into the Tools directory. Extract the DroidX root method into the same directory.
4) Start up ADB from a command shell. In Windows 7, you can hold the Shift key and right click in the directory to have an option "Open Command Window Here". Windows versions prior might have to go Start >> Run >>cmd, and then cd to the directory.
5) On your phone, enable USB Debugging from Settings >>Applications >> Development.
6) In the Command Prompt, type the following commands, followed by the enter key:
adb push spl-signed.zip /sdcard/1_33_2005_spl.zip
adb push exploid /sqlite_stmt_journals
adb push recovery-RA-dream-v1.7.0R-cyan.img /data/local
adb shell chmod 777 /sqlite_stmt_journals/exploid
adb shell /sqlite_stmt_journals/exploid
7) You will now see a $ sign. This indicates you are in the linux console on the phone. Type "rootshell" without the quotes, and press enter. It will ask for a password, enter "secretlol" without the quotes and hit enter. If all goes well, you will soon see a # symbol, indicating a root user.
8) Type "chmod 666 /dev/mtd/mtd1" and press enter.
9) Type "exit" and press enter.
10) You will now be back to a $ symbol. Type "flash_image recovery /data/local/recovery-RA-dream-v1.7.0R-cyan.img" without the quotes, and press enter.
11) Type "exit" without the quotes.
12) Now turn off your phone.
13) Hold down the HOME+POWER buttons, until the recovery menu shows up.
14) Select "Flash ZIP from SD Card"
15) Choose "1_33_2005_spl.zip"
16) Confirm by hitting the HOME key.
17) Reboot as requested. It will boot back into recovery.
18) On your PC, in the command prompt window, type "adb reboot bootloader" without the quotes, and press enter.
19) On your phone, verify that the HBOOT is 1.33.2005, and the radio is 126.96.36.199.
20) In the command prompt window, type the following, followed by the enter key:
fastboot erase system -w
fastboot erase boot
fastboot oem powerdown
21) Your phone will turn off again. Now, to put on CyanogenMod 😀
22) Boot into recovery again by holding HOME+POWER until the Recovery menu comes up.
23) Select USB-MS toggle. The SD card is now mounted on your PC.
24) Copy the following files to the memory card:
25) Press the HOME key
26) Select Flash ZIP from SDCARD, and flash in order: update-cm-5.0.8-DS-signed.zip, gapps-ds-ERE36B-signed.zip, and finally bc-5.0.7-eb1-signed.zip.
27) Once completed, select Reboot system now.
28) It will take 5-15 minutes to boot for the first time, but you are now running CM 5, or Android 2.1! Enjoy!