Question: The Windows Azure Platform allows an application to be deployed to one or more instances. The fabric controller then balances your application's workload across those instances. 

* Can the number of instances be scaled up/down based on demand or are the number of instances static? If instances can be dynamically started how much control do I have over how this happens?
* How does Azure balance workload amongst my application instances and do I have any control over how this happens?

Answer: 
I just want to add that by commercial launch (November), we'll have an API that lets you programmatically modify the number of instances. (So you can scale based on whatever logic you want.)
I know this is an old question, but I just thought that I'd highlight the free [Windows Autoscaling Application Block](https://www.windowsazure.com/en-us/develop/net/how-to-guides/autoscaling/), which was released since the question was first asked.