You want to make certain that key marketing objectives match key development efforts. You have a Market Map to identify the key market segments you're targeting.
What is the best way to capture compelling features and their benefits for each market segment?
For each market segment capture the key features and benefits that motivate to purchase the product. It is crucial that you list features and benefits together. Omitting one gives the other inappropriate influence.
Choose an ordering for your map that makes the most sense. I've had good results ordering first by time and then by difficulty/complexity. Others get good results from ordering by what the market wants or what sales can sell. Paul Germeraad from Intellectual Assets, Inc., has organized features into a product tree where the edges of the tree are the features in the last release. The features of the next release are placed around those edges. Paul draws lines around the features proposed for the next release. One advantage of this visualization is that the entire company can feel good about the growth of their product. Another is very practical: The expanding size of the perimeter correlates with the growth of the product development organization. As the product tree grows, so do the needs of the team in caring for and feeding it (including the maintenance team).
You have a representation of the key features and associated benefits needed to attack target market segments. This will provide the technical team with the data they need to update their tarchitecture map so they can realize these features.