We are already logging feedback posts in the Activity Log, but we are not displaying them because there are no stream files yet.
Let's add them!
@MichaelArestad will add mocks here.

Notes:
<Gridicon icon="caption" />@MichaelArestad - i've started on this in D17241-code
Here's a screenshot showing feedback submitted when the poster is known / logged in:

And when the poster is logged out / anonymous:

The reason i needed to simplify so much from your mocks is because we don't have a ton of useful data attached to the activity currently. We'll need to update Jetpack in order to capture more meaningful data, and it's a bit tricky because the form itself is highly customizable. We'd love for you and @joanrho to be part of the conversation on improving the data we capture.
So for now, do you think it's okay to release this simple version? The text is:
You've recieved feedback: <post title>
The post title will link the feedback post in the calypso editor.
The format of a feedback post title is a little strange:
<field value> - <date>
Where field value is the value of the first field in the contact form. Could be anything: email, name, favorite pokemon, etc
Perhaps a better phrasing would be
<title of feedback>
Feedback received
I think it would be more consistent with the other events.
Nice and simple. Thanks!
I've update the diff. Here are the new screen shots:

Added in D17241-code