Note: This article is based on a pre-release product and may therefor be subject to changes.

Yesterday, the Exchange team released the preview (you can also call this a public beta) of Microsoft Exchange Server 2013. The build version of the Exchange 2013 Preview is 15.0.466.10.

You can download the 1,5GB self-extracting Exchange 2013 Preview here.

Prior to installing Exchange 2013 preview, you need to install the following prerequisites depending on the targeted platform

Note: Clicking the checkmark leads to the download.

Note: When present, uninstall the Visual C++ 11 Beta Redistributable after installing the UCMA component. On Windows Server 2008 R2 SP1 you also need to register ASP.NET after uninstalling the VC++ 11 Beta Redistributable, before installing Exchange 2013, using:
%SystemDrive%\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -ir -enable
followed by an IISReset.

Required Windows Features
These cmdlets install the required Windows features:

Firewall
On Windows Server 2012, create an inbound firewall rule for port 139 when installing Client Access server.

Active Directory Requirements
Be advised that a minimum of 1 Windows Server 2008 Domain Controller and Global Catalog server is required in each site where you want to install Exchange 2013 Preview. Windows Server 2003 Forest Level is supported.

After successfully preparing Active Directory for Exchange 2013, the schema version will be 15132, Forest version 15448 and the Domain version 13236. More information on how to verify those values here.

To quickly check the level of your domain controllers, you can use the script provided here which will report the msDS-Behavior-Version attribute (3 = 2008).

Order of things
Microsoft recommends you install Mailbox servers before installing Client Access servers.

IPv6
Like Exchange 2010, Exchange 2013 supports IPv6. However, a pure IPv6 environment isn’t supported, so IPv4 is still required.

Co-Existence
Everybody who’s still running on Exchange 2003 (many customers are) need to follow an intermediate upgrade path when moving to Exchange 2013 when it goes RTM, as co-existence between Exchange 2013 and Exchange Server 2003 isn’t supported. Note that the preview version isn’t supported in co-existence with any Exchange version by the way.

Release Notes
Be sure to also check out the Release Notes here.