If you check out GitHub (GH) Explore regularly and you are also a bitbucket user, you may already found bitbucket (BB) Explore's trending is pretty much stationary, bit GH's is not. I am not saying GH's is better, but you want to discover new projects and that's main purpose why you visit Explore page.

As you may notice GH uses Topsy to provide the list along side with featured repos by Changelog. I guess BB's trending is based on the pageviews data on BB's server, BB also has featured repos and tweets mentioning bitbucket.

I found it is not hard to get the similar list on Topsy which you see on GH's Explore. From that, you can have a list for BB's repos. It is not only from Twitter, you can also choose data from Google+.

If Topsy API was not commercial, I would already write some code more my convenience because reading through those results on Topsy is not as easy as you read the list on GH's or BB's Explore. Right now, I've bookmarked it, it's better than that stationary list.

Hmm... Topsy also provides email alerts and RSS feed, maybe filter with Yahoo! Pipes?