Clean design inspires confidence. I looked at BitBucket about 2 years ago, and just didn't have enough confidence in it, but recently created quite a few repo's on it and am using them everyday. The new re-design makes all the difference in gaining my trust.
At least that's how I see it.
I agree with you. Even though BitBucket allowed private repositories for free, their poor usability and interface kept users away. GitHub is not just Git. GitHub would have become popular due to its ease of use and cool user interface even if it was based on Mercurial (hg) or, may be, even Darcs. Bitbucket's latest design is good but has arrived later than expected.
Definitely. I remember checking out the BitBucket repo for pygments a while back and noticing how clunky the ui was compared to github. The new redesign at a glance seems like a huge improvement.