As you may know, Application Request Routing (ARR) has a host name affinity feature that is designed specifically for hosters to use to maximize the available resources across their environment. More info on host name affinity and hosting can be found here and here.
I am happy to announce that one of our partners, MaximumASP has launched a private beta hosting offering based on ARR and IIS7/IIS7.5. To quote MaximumASP, the MaxESP - an "Elastic Shared Platform" offers:
...while most of the great features of MaxESP are below the surface, such as load balancing, SAN storage, redundant web servers, etc., you can opt to have your website clustered across multiple servers.
...allow your website to run on a single or multiple web servers simultaneously. Down the road, we'll be expanding this capability so that you can select as many web servers as you want, and move your resources around dynamically as the situation demands.
The elastic scalability per host name is achieved by a combination of host name affinity feature and the ability to assign the number of servers to consume per host name in ARR. A step-by-step walkthrough on host name affinity is found here.
Congratulations to MaximumASP for the successful launch. You can also learn more about MaxESP at MaximumASP's blog site here.