Stick this in your user.js file. Only tested in current Titanium code

spaz_embedly_previews.js

jQuery(document).ready(function() {
	
	
	/**
	 * remove this default filter from these timelines -- we'll use embedly below
	 */
	Spaz.TimelineFilters.friends.removeFilter('getImageURLs');
	Spaz.TimelineFilters.search.removeFilter('getImageURLs');
	Spaz.TimelineFilters['public'].removeFilter('getImageURLs');

	/**
	 * A helper to load media via embedly 
	 */
	var embedly_listener = function(e) {
		/*
			loads media
		*/
		jQuery('div.timeline-entry.new div.status-text a').embedly({
				maxWidth: 250,
				maxHeight:300,
				'method':'afterParent',
				'wrapElement':'div',
				'className':'embedly'
			}
		);
	};


	/**
	 * add listeners to these hooks
	 */
	Spaz.Hooks.register('friends_timeline_data_success_finish', embedly_listener);
	Spaz.Hooks.register('search_timeline_data_success_finish', embedly_listener);
	Spaz.Hooks.register('public_timeline_data_success_finish', embedly_listener);
	
	
});