All though it's not that original, it does have it's differences in the top nav to make it a bit unique and YES, it is very efficient as it looks.
That's the burden they'll have to carry for not having its own search engine under the Yahoo! brand back in the late 90's until finally deciding
to go with Google for "for its award-winning advanced search services, which use powerful technologies to determine the importance and relevance of Web pages". It's perfectly understandable, they have to stick to what works well in consumer's taste for acceptance, and Google's layout works really well. Along with everything else that made Google #1.
Can Yahoo! ever take the #1 position in search? I don't know about you guys, but I'm so glad to see that the search wars are much more competitive and the pie is breaking up nicely.