Related discussions in https://bitcointalk.org/index.php?topic=46429.0, https://bitcointalk.org/index.php?topic=45211.0, https://bitcointalk.org/index.php?topic=46538.0. The basic idea - allowing more-complex scripts to control the conditions under which coins are released - is good. However, I prefer the versions that keep the address format the same, or at least very similar. Allowing complicated addresses puts burden on Bitcoin-handling web sites and breaks compatibility in ways that it doesn't need to be broken.