I am sure you would have heard of Google's OneBox. It's a way of searching multiple aspects/types of information with just one search keyword and submit. They've been quietly rolling it out to people, who don't even know that it's something new on their part. They would have just been noticing a flurry of new results showing up, and would have have nothing more than Google becoming a little more useful (noisy?). I think it's a brilliant move.
Lessons from SearchMash
SearchMash is Google's playground for technology and new interfaces. It might be more than that, but that's all you get to see anyway. On that page, they have various modules on the sides which give you search results from videos, news, Wikipedia etc.. They've learnt well from seeing results from that page I guess, and have integrated it rather nicely into the mainstream Google search, by removing the clicking through other modules and just showing you the results. If you make people click for more info, they might not click. We have been trained to automatically filter out unwanted results from results automatically. It all adds up pretty well.
I think it would have been better if they would have announced it, and let people know of the various ways they can access results, giving preference to some based on what you're looking for. The latest addition to the OneBox results is information from Wikipedia. All you need to do is append an 'info' to your search term, and Wikipedia results will get bumped to the top. A very good way of searching Wikipedia and Google together :)
Eggs in one basket
As I've spoken about integrating things before, I'll commend Google for doing this because it just saves everyone the trouble of searching for different types of things separately. However, this method has a quickly-obvious pitfall. Google doesn't know which info to give preference, so you might have hunt through to get that perfect match. But this is not that major, so it's alright.
It would be ideal if Google 'learned' from the various searches being performed individually for the different types, and then try to match the relevancy to the search being performed. I don't think they already do this, but they should try and learn from the links people click from searchesThey know which one's you do, since you can go to your Search History and find the links you clicked on for a particular search., and rate them higher for the people. Sort of like a 'click-recommendation' in tandem with a 'link-recommendation'. More clicks, more votes. A simple little addition, but one that could really help.
I just love the way Google thinks. They make thinking up other not-so-probably stuff so much easier :)