This is excellent news, SPF and Microsoft Caller-ID is converging. I haven't looked too much into the details, but from a quick glance it's looking great. Instead of SRS (the funny rewriting of the envelope sender) we'll get a new header to add when a mail is being forwarded. I never thought SPF was quite done and was a bit disappointed it was being pushed as "good enough" to get adaptation sooner rather than getting it a bit better first, so I am very excited about this. The new SPF will have a much better chance of widespread use.
Meng Wong made a slideshow of the new SPF
