It looks like the original code from Erik Cederstrand to download the WSDL from the server has been taken out. The WSDL and XSDs which are included in this project are for Exchange2010_SP2. Attempting to use this on an older server would result in the following error (from Exchange2010_SP1):
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
<s:Body>
<s:Fault>
<faultcode xmlns:a="http://schemas.microsoft.com/exchange/services/2006/types">a:ErrorInvalidServerVersion</faultcode>
<faultstring xml:lang="en-US">The specified server version is invalid.</faultstring>
<detail>
<e:ResponseCode xmlns:e="http://schemas.microsoft.com/exchange/services/2006/errors">ErrorInvalidServerVersion</e:ResponseCode>
<e:Message xmlns:e="http://schemas.microsoft.com/exchange/services/2006/errors">The specified server version is invalid.</e:Message>
</detail>
</s:Fault>
</s:Body>
</s:Envelope>