Ideally I'd be able to include a URL perimeter (or #) in an incoming link to be a triggering event.
Be able to go through a series of Conversion to build a Quiz/Survey type Conversion.
Add possibility of using a countdown timer on the Conversion block.
Add ability to split test mulitple Conversions to see which one converts the best and then use that one automatically after a certain period of testing.
Documentation is missing about which email marketing tools Conversion can integrate with. And how to go about integrating with them.
Update the analytics to show the daily conversion rate as well as over a period of time
An option to add a conversion inside a page or post, for example, after the first paragraph would be a nice way to show inline ads or conversion items and be able to track conversion rate.
Add an option to only show conversion item if a specific product is in the cart.
Only show items if the user was referred from a specific domain like facebook or twitter