The search results already have "profile_image_url" which is the "from_user" profile image, but could the "to_user" have its profile image url included as well. This avoids me making multiple calls and hitting your server unnnecessarily.
It would clearly only be included/filled when there is a "to_user". I think the bandwidth overhead would be minimal, if not it could be added thru an extra parameter "&extended_user_data=1" or "&include_to_user_profile" so it could be selectively used if required. This addition enables me (http://coderanger.com/twitcher) or other apps to properly attribute the search results like a normal user status.
