In a post on her blog this morning:

Because I promised you the behind the scenes, I figure I should alert you to the fact there is a good chance that I will shut down GretaWire soon. As you might have guessed, it is really time consuming (I do it alone) and I am trying to think what else I can do on the web. I would like to expand into other areas. It has been lots of fun blogging and building GretaWire with all of you but I, probably like you, like to dream about doing other things – whatever that may be.