We didn't bank it, because 10 years ago, that wasn't really even an option. We did, however, donate it to a public blood bank. Earlier this year, we got a call from the blood bank asking us if we were still willing ot have it used to save someone's life. We were, and it did. Someone who otherwise wuld have died got a second chance at life due to the cord blood that otherwise would have just been thrown away. Cord blood is amazing stuff - flexible and filled with stem-cells.
I blogged about it earlier htis year, if you want ot read the whole touchy-feely story: http://www.justcauseit.com/blogs/alyssa-royse/my-daughter-saved-someones-life-today
That said, if we had it to do over (which we don't, there will be no more babies for us) we would bank it. Even if the research is inconclusive now, no one knows where we will be 10 years from now..... And for me, the $2k or so is a gamble that's totally worth it. And most of them have payment plans etc.... I'd do it, but then, I've seen it work, first hand....