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: 
This question has lots of good information, including a 3rd party tool (AzureWatch) that I use that can scale up/down based on load.

[Azure platform: scalling instances up and down](https://stackoverflow.com/questions/2136035/azure-platform-scalling-instances-up-and-down/3885467#3885467)
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.