With the announcement of the Motodev core plugins being included in the AOSP tools (http://developer.motorola.com/tools/motodevcoreplugins/), I have been trying unsuccessful
Look at the errors, they provide information about the tools you are missing. After I've gone through the motodev tutorial, I had to install Web Service Tools, Database Tools (DTP) and Memory Analizer Tool (MAT). Also, Leoa is right, for people using windows, stick with win32, even if your windows is x64.
After two days I got MOTODEV Core Plugin to work in Eclipse. In general follow these directions http://developer.motorola.com/tools/motodevcoreplugins/
I got it here: http://download.eclipse.org/eclipse/downloads/eclipse3x.html
ADT https://dl-ssl.google.com/android/eclipse/
http://download.eclipse.org/sequoyah/updates/2.0/
4.When installing MOTODEV, Remove MOTODEV packages you don't need like linus, macos and com.motorola.studio.android.wind32.x86_64
At this point, there should be no errors in your project.
Now to run MOTODEV, select package com.motorola.studio.android and run as 'Eclipse Application'
Next a window will open that has the MOTODEV menu in the main window.