Well, we always see, hear, and read about the list of NEW features in the myriad of articles, columns and blogs on "What's New is Denali?". So, I changed my title to "What's OLD...?" More succinctly, what features are being removed or that 4-syllable word that strikes fear in the hearts of us mortal DBAs - "deprecated" There are many resources on this topic as well, but I will share the current list as of SQL 11 CTP1.
In keeping with that definition, Microsoft will announce, usually with the release of the CTPs, the features that will be deprecated as of the new version. Remember, just because it is announced that the feature is "deprecated", doesn't mean it is automatically "removed". (see above definition "the gradual phasing out....") As Microsoft officially states, [when you see a feature that is being deprecated] "we are only announcing [it], so [the feature] will be around for three (3) more versions" This is the 3-version process by which we end the lifecycle of a feature. Therefore, when the feature is referred to as deprecated, it certainly is almost always still existing in the product, but, as poetically put "on the journey to being removed." Ahh, slow retirement without a pension :-)
Seriously, though, it should give several project/IT managers, sql developers, architects and DBAs ample breathing room to phase out the the usage of the feature, and prepare to utilize any replacement (new)features or workarounds in their code and processes.
So, what are the features being deprecated in the "next" version? Here is a pretty comprehensive gridsheet, which lists the category, deprecated feature, replacement, if any, feature name, and even a feature id. We are warned that the documentation is for preview only, and that the list itself is subject to change in later releases. In fact, I'm fairly certain there will be even more features added to the deprecation list in the upcoming CTP2 release, and we'll be able to mention them more at-length then.
As stated in the MS Technet reference, "this topic describes the deprecated SQL Server Database Engine features that are still available in SQL Server Code-Named “Denali”. These features are scheduled to be removed in a future release of SQL Server. Deprecated features should not be used in new applications." Good advice :-O
In addition, BOL should also contain references to deprecated features, so be sure to always look there as a reference too. For those who always look for a way to derive info via script, you can also monitor the use of deprecated features by using the SQL Server Deprecated Features Object performance counter and trace events. Here is a simple script, that can be used for versions SQL Server 2008 and higher:
SELECT instance_name FROM sys.dm_os_performance_counters WHERE OBJECT_NAME like '%Deprecated Features%' and cntr_value > 0
Hope this helps!