Are there any specific changes under the hood in 2013 vs 2011 SP1 that are noteworthy from an architectural and installation point of view - for example I've heard COM+ has now been dropped for the CM?
From an installation point of view, there is no more Database Manager tool, to install or upgrade the databases, you use PowerShell scripts.
Another thing to note for upgrades is that there is no Logging database for 2013 anymore, so on a fresh install you don't create one and for an upgrade you can drop that database.
COM+ is not installed by default, it has become optional in 2013 (its currently still there for backwards compatibility, but you have to specifically add it)
One of the big things to note is that the Content Manager will only be supported on the following operating systems:
- Windows Server 2012
- Windows Server 2008 R2 SP1
This will mean that only 64bit operating systems are supported!
On top of this, it is worth noting that .NET version 2.0 will be deprecated on the Content Delivery side (from a .NET perspective), with only .NET v4 and v4.5 supported.
On the client side IE7 & IE8 will no longer be supported.
From a DB standpoint, the Items_states table is now merged into the Publish_states table
One of the biggest change is that the component_presentation table has been updated from ntext to nvarchar(MAX) type for the Content column.
2013 deployer now publish encoded or even strange Asian character into the broker database so you cannot query the component_presentation table directly. Fetching it via the new 2013 CD API will work fine though