A short while ago, I wrote a blog entry about SQL Server 2012 features that are currently available in SQL Azure. In that post, I mentioned that Ed Katibah would publish an article detailing the current state of the SQL Server 2012 spatial features in SQL Azure, in detail.
That article is now available at the Technet Wiki. Note that not all features are available currently, and Ed has a nice detailed chart that covers this feature-by-feature. Thanks, Ed! And, as with the SQL features in SQL Azure, the available spatial features will increase in future as parity with SQL Server 2012 RTM is acheived. Watch this space.