Or so it's being reported (here and here).
I'll repeat now what I said earlier. In my opinion, the amount of uncertainty about these things far outweighs the perceived differences between potential nominees. In other words, we have estimates from various pundits and experts about the points on an ideological line where the various rumored nominees will fall. I think we're all kidding ourselves, however, if we think these are anything other than very, very, rough estimates. Not only is it impossible to know exactly how any potential nominee will vote once on the court (even if she has an extensive paper trail; writing a law review article, giving a speech, and even writing a lower court opinion are just very different things than participating at the Supreme Court level), but the truth is we really have no idea what the key issues are going to be over the term of a nominee. Especially when the president follows the current partisan incentives and chooses a young nominee.
Now, that's not to say that all potential nominees are identical; it's just that we really can't know enough to rank them, either on specific issues or on general ideology, with any certainty at all. So in my view, all that liberals can ask of a Democratic president (and all that conservatives can ask of a Republican president) is someone who will be basically reliable, someone who will generally line up with the "correct" side. I do think that that much is possible to do, and I think that Elena Kagan certainly appears to meet that standard. Beyond that, it's all guesswork and crystal-ball gazing, and I think that any liberal who believes that it is certain that one of the other potential nominees was better -- again, on either specific issues or general ideology -- is just blowing smoke.