We already we aware that as a result of the time-leap on Desperate Housewives that some recasting would be required, mainly of the younger cast members.
Now there's finally some new names:
Joshua Moore is set to play Parker Scavo, Charles and Max Carver will take on the role of twins Porter and Preston, and Kendall Applegate will play Penny (formerly a baby).
An IMDb search reveals little details about all of these children, so I get the sense they are relative newcomers...
Finally, E!Online shares a lot of interesting tidbits about the direction of the new season of the show in this article.