Benefit of Websphere Portal and Lotus Domino together

As big customer base on Notes/Domino world wide, Domino is recognized as a successful and reliable application infrastructure. Why not using this as our portal Framework to save existing investment of our customer. What is the benefit of putting Websphere Portal and Lotus Domino together?
One of the most common challanges in developing large-scale Domino Web applications is to make Domino HTTP to access scale and perform well under a heavy load. It is possible to do that but it needs a lot of efforts and experience to implement the cache strategies.
In order to combine the strength and scalability of a J2EE application platform with the strong collaboration and document-centric capabilities of Domino. We may need to know the benefits to combine Portal and Domino :
1. Deeply Integrated : Websphere Portal provides the most robust integration with IBM's entire SW portfolio including Lotus Infrastructure
2. Open : Integrate Lotus Domino to become key open standards for portal industry
3. Secure : You can use Lotus Domino Directory with Portal to provide granular security level
4. Flexible : Provide Domino application with a wide range of client devices
5. Global : Supports multiple languages to support your organization
Next, I will continue to post some blog documents to show how can we portalize a Domino application