Since CU1 is available it is possible to implement Exchange 2013 in an environment which contains Exchange 2010 SP3. This will create the option to migrate your resources to Exchange 2013. As you may now the Exchange Management Console (EMC) is replaced by the Exchange Admin Center (EAC) a web based admin tool.
The EAC is accessible via the url https://fqdn/ecp for those who are familiar with Exchange 2010 will see this is the same url as for the Exchange 2010 Control Panel. When Exchange 2013 is implemented you would like to check somethings and maybe configure several things via the EAC.
To do this go to _https://fqdn/ecp _and you will see the following screen:
Provide the username and password and login:
But what you will see is the Exchange Control Panel. But how can you get to the Exchange Admin Center?
To do this you will need to add an additional parameter to the url https://fqdn/ecp?ExchClientVer=15. The loginpage will be displayed again but after you have provided the login details you will see the EAC:
A simple solution but which can take pretty long before you have found this specific thing.