2 small instances and storage for free. Its a great offer - we host our bootstrapped node.js application on Azure and it works great - and is net free for us.
It's actually more flexible than that too. You get 1500 hours of small instance credit, but you can apply it to larger instances sizes (for proportionally less time) or other services like "Websites" which I haven't used but is apparently some sort of PaaS.
I was looking for this detail - and not sure where it says you get 2 instances free. Can you post a link?
Edit: I did my math wrong previously. It is 1500 hours/month.
1500 hours a month - so for a small instance that works out to 2 instances. Eli below has it right - you can scale that up as well and get a smaller number of free instance time.
Can you also choose to use (more than 2) extra small instances? They provide better bang for the buck than the small instances.
Sure. And you have 10 of those MSDN subscriptions, one for each developer. You can't use say 20 small instances for one site, but you can use 2 instances for 20 separate sites/services.