Since microsoft released TFSPREVIEW (tfspreview.com) we were wondering how to connect AX 2012 TFS client to TFS cloud provided by tfspreview.com

We were finally able to connect without any custom, just point ax tfs configuration to the following address: 

https://<yourname>.tfspreview.com:443/defaultcollection

Just use your live id in the credentials pop-up and you should be fine. This was tested with AX 2012 Feature pack

Now you can leverage the power of SaaS that tfspreview.com provides along with the bug tracking, agile templates and much more...