Ok, Ok...its time to add my $.02.
The poster "[email]" is clearly *not* the real Jerry Seinfeld. The true poster played a joke on anyone who actually fell for it. One poster already posted the nslookup information showing that no such sein.com host exists, etc, etc.
Its really not that difficult to forge posts to be whomever you want. One could easily create posts from [email], [email], [email], even [email]...I am just not bored enough to actually do it. In addition, there is the anonymous mail server which will post using whatever nickname you wanted.
In conclusion....*ITS NOT REALLY JERRY*.
Dave