I've come across a few instances where translated strings in GlotPress somehow have not made it to the live WordPress.com site.
In my case, I'm translating Chinese (Taiwan) words, I've set both my blog and global user settings to zh-tw.
In GlotPress, I'm looking at the string "At a Glance" which has been translated and added since 2010-01-08, but on my dashboard, it still displays in English.
Is that a (known) bug? or am I not looking at it right?