Twitter has unveiled the redesign of their homepage and it's clear they're dedicated to search. (You'll have to sign out to view it.) They now serve up a central search box as the main feature with trending topics below in almost a tag cloud style. The top row, with the biggest font features current hot topics. The second row with slightly smaller font features hot topics from the past day and finally the third row with topics from the past week.
I think it would be nice to incorporate the design more inside the sign-up wall. It looks sharp and the main reason I go to the Twitter site is to see what's trending or to conduct a search. I use a desktop and mobile client to do my actual Tweeting.
Twitter does have plans to keep working on the entire site, so they remain a site to watch as they continue to incorporate their strategy.