Fixing 68 tickets, WordPress 2.7.1 is a maintenance release, not a security release, and so it doesn’t appear to be a “have to upgrade right this second” release, but I would definitely give it a go if you have been waiting for a point-one release or if you want to test out the core upgrade feature in WordPress 2.7.
From the WordPress blog:
2.7.1, the first 2.7 maintenance release, is now available. 2.7.1 fixes 68 tickets. You can automatically upgrade from 2.7 to 2.7.1 via the Tools->Upgrade menu, or you can download the package and upgrade manually.