Do URL shorteners pass anchor text? - Matt Cutts video

...Now, just to let you know, if you look at Twitter's web pages, many of those links have a nofollow link, so those links that are on the web page may not flow PageRank, but we may be able to find out about those urls some other way, maybe a data feed or something like that. But just url shorteners, as far as how they relate to SEO, are not necessarily unfriendly at all. The vast majority of url shorteners have a good uptime, and also pass PageRank and anchor text, because they have a 301 redirect.