Yes! We would like Salesforce tasks that are created by Marketo to be related to Salesforce Accounts vs. Salesforce Opportunities so being able to select different options in the "Related to" field is important.
We track all of our prospect / customer history on the Salesforce Account object so having Marketo tasks connected to the Opportunity object is causing issues for us. eg. If we delete an Opportunity, we lose all of the Marketo prospect / customer history that was attached to the Opportunity unless we manually move each task over from the Opportunity object to the Account object... painful...