iWeb will still live
I'm not happy about the idea of iWeb not getting future updates, but iWeb will be able to live on after July 2012. As long as the OS will support it and the App will run, you can always upload any iWeb site to a web host other than Mobile Me. I suspect iWeb will be supported for several years to come in future Mac OS. If a new iWeb App is not offered before July 2012 though, I will be looking for a new website builder. Hopefully a good alternative will emerge by then. Until then, my site will happily live on at the Host Excellence Servers, well after July 2012 if needed.
iMac 3.06 GHz Intel Core Duo 2, 21.5, Mac OS X (10.6.7), 4GB Ram, Airport Extreme/Express