Very helpful, thank you bel and Fraser ^
No, there is no need to read between the lines. I have already suggested that surely he could just enter under the VWP - he has in the past a number of times - (with plenty of evidence such as return air tickets, maybe proof of employment in the UK, proof that they're getting married) but the worry is the comment from USCIS that arrival while a visa application is pending gives a "slim" chance of entry. I guess a significant difference between the situations of Fraser and my friend is that Fraser had already been granted a visa but chose not to use it, while my friend has not been.
My personal opinion is that he would be fine, but there is quite a lot riding on it...!
I'll suggest contacting the British Embassy and the Congressman but USCIS said that they're only now looking at applications submitted in Oct 07 so I'm not sure how successful that route would be. However, I wonder if applying for a single-entry visa may be an option?