Adam,
Our next release which is expected to be out in a month,will have the new connector for Liberty Profile.
To get it working in MEB 2013, you need to enable the deprecated WTP capabilities. Go to Windows > Preferences > General > Capabilities > Advanced > MyEclipse Standard Tools. Check ‘WTP Deprecated’ and ‘WTP Extras’. Apply the changes.
Now switch to WTP Perspective to see the WTP Servers view. When you try to define a new server under WTP Servers, you will see the WAS V8.5 Liberty Profile listed under IBM. Select it and follow the wizard.
Here is the screenshot for your reference :

I tried to install “WebSphere Application Server Developer Tools for Eclipse Juno V8.5.5” on MyEclipse Blue 2013 SR2 and I ended up seeing dependency conflicts. I then tried “Websphere Application Server v8.5.5 Liberty Profile Developer Tools for Eclipse Juno’ and installed only the WAS Liberty Profile Tools (Unchecked the other components.)
Let us know how it works for you.