Techcrunch recently posted about how Google and Bing have made deals with Twitter to add searching "Tweets" to their services.
They mention ranking tweets as being a hard problem to solve... at first I thought what is so hard? You already have twitterholic, twitterank, and twitter grader. Twitter Grader seeming to be the most in depth and informative, while TwitterRank comes up with an ambiguous number (hurray! I am 15.93... whatever that means) and Twitterholic comes up with a rank for the site as well as a rank for your location.
However, it is the "real time" aspect of the search that seems to be the issue. When it comes to Tweets, it is all about timing and keeping ahead of the latest and greatest wave of information. When you search on Twitter, you find the most recent posts which have nothing to do with relevancy or ranking mentioned above. If I search for Bing today, I would want to see tweets about how Bing is now searching Twitter. I would not be interested in tweets about Bing's initial release months ago, even if those older tweets were from @Bing itself.
So there is the rub. How do you obtain the most recent AND most relevant posts? It will be interesting what they come up with. It would be great if they could track the number of times a tweet has been Retweeted, but I am not sure if that is a possibility especially considering how many retweets either get a comment added to them or they get edited down to fit in the user's name.
If it were up to you, would you put more emphasis on how recent the post was or how highly ranked the user is?