I'm having the same problem. Also Win7 (64bit if that matters) with a Droid X. Sounds like TuneSync would be great, but I just can't see any playlists.
In case it helps, when I try to run the "test connection" process, TuneSync gives me what appears to be a MAC address for my computer instead of an IP, and then tells me the connection to computer failed. Doing an "ipconfig" on my PC shows that I have a normal x.x.x.x style IP address, though...
I finally got this working by running both itunes and tunesync server as an admin. (right-click --> run as administrator..)
I still couldn't see the server in the list so I added the IP manually then the playlists showed up.
For what it's worth, I've been using iTunes Agent (free app: iTunes Agent) and it works great. Just install it, run it after starting iTunes, and configure your device. I transferred ~10gb of music to my phone in about 3hrs, and from there updates are plenty quick. My only complaint is that it doesn't keep track of whether songs are played or not, so your play count in iTunes won't ever change. May not matter to most, but it was always an interesting stat for me.