I've been waiting for this since the Voyage came out. I had hacked all my older Kindles and reverted to using my Paperwhite because I missed my own screensavers so much and couldn't put up with the stock ones. When I saw this tutorial and that it didn't involve using Linux I decided to take the plunge.
Some notes:
1. The Kindle Voyage is really easy to open (which was kind of a concern for me beforehand).
2. Soldering the serial cable seems next to impossible to me - I used the pin method which works fine if you fix everything tight with tape (you do not need to see the screen for hacking and installing). - I put three pairs of reading glasses on on top of each other to position the pins correctly...
3. I ran into the same issue as
stupidhaiku, the boot also stopped with the line "sock_init 1888". Thanks to his post I was able to proceed and login.
So I am a very happy owner of a jailbroken Voyage (FW 5.6.1.0.5) with custom screensavers ;-) Thank you all very much for your work and your posts!