New in SOAP Client v1.6.3:

'View WSDL Source' option (think 'view source' in your browser, but for WSDL ;) ). This is accessible under the View menu or with the (Safari-esque) command-option-U keyboard command.

command-, now opens a small Preferences window with a setting for wrapped vs non-wrapped text in all raw source text views (SOAP Request, SOAP Response, and WSDL Source).