I asked the question but did not get an answer to it. Now i understand how get all block in pages, but i get only current page blocks. For example:
$layout = Mage::app()->loadArea(Mage_Core_Model_App_Area::AREA_FRONTEND)->getLayout();
/* then i get all blocks from that page*/
How to get frontend area, when i in backend?? I know that it should be simple, but when i want get AREA_FRONTEND, i get my current page, but i need get frontend area.