i figured it out myself , i incorrectly had the login entry coded wrong above too. here is what i ended up with
VimClient
client = new VimClient();
client.Login(
"https://10.10.1.1/sdk", @"test\admin", "password");
NameValueCollection filter = new NameValueCollection();
IList<EntityViewBase> esxList = client.FindEntityViews(typeof(HostSystem), null, null, null);
foreach (HostSystem host in esxList)
{
string hostname = host.Name.ToString();
string version = host.Summary.Config.Product.FullName.ToString();
MessageBox.Show(hostname);
MessageBox.Show(version);
}
and it returns the esx host names and version