Note sure how V2010 works, as I only have V2007. So...
I think if you right click the Page tab, you can choose Page Setup. That should bring another menu, choose the Layout and Routing tab. Hopefully, there is an option to select "Move other shapes away on drop." Enable that feature. That ought to do it. If a shape changes size, the other shapes around it will move.
Don't know if Dynamic Grid has to be enabled or not.
HTH
Wapperdude.