Yesterday, the Poptropica Creators posted on their blog a sneak peek of the new island. Here it is, exactly (I copy & pasted):

Tuesday, June 1, 2010
Sneak Peek of a Rusty Robot
I received special instruction to reveal to you this mysterious image. Be wise. With this small piece of information you could save the future of Poptropica. Your mission, for now, is to wait patiently until further notice.
Sneak Peek Picture