It feels like there have been a lot of these announcement posts lately, but that's because a lot of software is getting released. This online release of the Orcas samples should take care of everything relevant to WCF developers that has come out in the last week. My understanding is that you should use the online version of the samples in preference to other sources, such as the Orcas install download.
There are quite a few readme issues related to the samples. You can get all of the details about these issues from my earlier post on the Orcas release.