VERBOSE: Connecting to EXCHANGE01.domain.com [exchange01.domain.com]
Connecting to remote server failed with the following error message : The WinRM client can not process the request. It cannot determine the content type of the HTTP response from the destination computer. The content type is absent or invalid. For more information, see the about_Remote_Troubleshooting Help topic.
+ CategoryInfo : OpenError:
+ FullyQualifiedErrorId : PSSessionOpenFailed
This is what I get in the shell, something similar I see when I try to login to the GUI googling provides a lot of information, mosly irrelevant. For example http://msexchangeteam.com/archive/2010/02/04/453946.aspx has a lot of info, but the described options do not appear in my system at all (the powershell part in IIS has no KerbAuth option at all)
UPD: fixed by removing and installing the WinRM feature