Via Christian Weyer, Mindreef has released SOAP Scope 4.0! 3.0 is an awesome tool, so I'm anxious to get the upgrade. For anyone working with web services intensely, I recommend this product wholeheartedly. It is absolutely essential. I'm also hoping to see if they've managed to trim the working set down siginificantly which would creep up to about 100 MB in 3.0. Stay tuned for an update.
After installing SOAP Scope 4.0, I read the known issues. It warns that Windows XP SP2 has an concerning the loopback address for which you need a hotfix. Mindreef recommends calling (Microsoft Professional Support) to obtain the hotfix.
Microsoft was very good (read: fast) in making the hotfix available.