I think some folks sense blood in the water around MySQL, and are trying to grow marketshare.
I plug postgres constantly, myself, and I do want to see it get more popular and have a larger community of support (heh, although more users can mean the inverse of supportive community!). I do think it's a superior technology to MySQL, but every tool has its place. Would be good for more people to know the elephant is out there, and all the cool stuff it can do :-)