Barry's coverage of the Search Engine Q&A on Links session at SES San Jose 2006 is a must read. I've pulled out a few of the more interesting (to me) segments that tend to answer questions we've all bandied about for years. For full details, be sure to go straight to the source.
Regarding same anchor text - Adam Lasnik from Google says "if all the links say the same thing about you, then something is a bit sketchy."
Regarding getting links slowly - Google, MSN, and Ask all agreed that the speed of link acquisition doesn't matter. What matters is that they are relevant and natural (i.e. no arm-twisting, buying...). Yahoo was a little more unclear in their answer, not referencing speed, but emphasizing organic and natural.
Regarding bad neighborhoods linking TO your site - Google says links are only one indicator of trust, and bad in-links by themselves won't hurt. Yahoo says they will manually review a site if the bad in-links go above a certain threshold. Ask says bad in-links will simply not be counted. MSN mirrors Google in saying that as long as there are positive signals of quality, the bad in-links won't matter.
Regarding page trust vs. domain trust - All seemed to agree that there are times that the trust of an entire domain may come into play with rankings, but not always. MSN gave a good example of Geocities, where it wouldn't make sense to pass along domain trust to each of its pages.
Regarding 301s passing along full credit for backlinks - Google and MSN both agree that a 301 will eventually pass full credit (not instantly, but it will happen).
