Lori,
We just added this capability in the March release and I can confirm that it works. Please make sure you create (not clone) a new video asset in order to use the &autoplay=1 argument. My configuration is shown below -
![0EM50000000QFNX.jpg 0EM50000000QFNX.jpg](/t5/image/serverpage/image-id/9475i6B73E3784A17FC00/image-size/large?v=v2&px=999)
Here is the LP with the video that autoplays - http://na-qe.marketo.com/lp/socialoct/Raj_social_TarzanVideoLP.html