EDIT : Saying all this, I just tried it, and, like you said, it seems to attach the Email from outlook as an Activity, rather than an HTML Email, which I assume is the key to tracking. So unless there is a way to attach the Salesforce2Outlook email as HTML Email, its unlikely.
It is an idea, so surely not possible then
Most email tracking works by using a one pixel image, a link to which is embedded in the body of the email. This link is to an image stored as an externally available 'document' on your Salesforce org. So when the recipient opens the email, the link is accessed, which is used to track the email.
In theory if you were to insert this img link tag in your HTML email that you send from the Outlook Connector, it should still work as usual.
Here is a resource explaining how this works with templates
However, it goes without saying that tracking is also dependent on the recipient's mail client not blocking out image content, which MS Outlook does (depending on security settings i presume).