Windows Azure is a great platform. There is however a massive hole where the documentation should be.
This is the list of the azure vm’s:
http://msdn.microsoft.com/en-us/library/windowsazure/ee924680.aspx
If you don’t want to use the latest guest os (if you do the upgrade plan is entirely at the mercy of the Azure OS team) then you need to stay no more than one version behind the latest. Fall off the list and then you can’t redeploy after 60 days. This is not helped by the poor quality os version details.
Here is the rss feed (http://sxp.microsoft.com/feeds/3.0/msdntn/WindowsAzureOSUpdates)
Here are some choice extracts:
Guest OS Matrix page to be updated April 2nd
The Guest OS Matrix page has been frozen pending updates for the BUILD conference. See this RSS feed for the latest Guest OS updates until that time.
No MSDN Guest OS Matrix updates until Jan 9th. December 2013 release info on RSS feed
No MSDN Guest OS Matrix updates until Jan 9th. Dec Guest OS release information to appear on RSS feed
Both of these are incidents where the key documentation is not updated in a timely fashion.
For example 3.12 has been released but the documentation says pending.
Theoretically 3.13 should be but is not.