The AngloBapitst, Tripp, has some more interesting stuff from NWCU, on on "ecclesial malleability" and un-churched Christians and Gen-X and Gen-Y. According to Tripp this post of mine expressed something like some of the views expressed in the seminar he attended on the third day of the conference.
Here's something the Orthodox and RC may need to keep in mind both in these sorts of conversations and dealing with the Emergent Movement(EM); you are viewed as simply a denomination like every other Protestant group. I mention this because I run up against a criticism of EM and its often eclectic and cafeteria style worship practices and faith, from both Orthodox and RC on in the interwebs. I do understand the criticism and while I myself do borrow and make use of elements of traditions that are not my own (I write icons and they are used in Reconciler's service) I do not simply appropriate them as a Protestant but attempt to allow the practices and elements transform my own faith. I also recognize that my attitude is not necessarily shared by all who may do the borrowing. I will also admit that this borrowing from your traditions is not necessarily done well, or carefully or with consideration of the full meaning of what is borrowed in the context of the Faith. However, I think many are doing this to find the continuity of their faith with what has gone before.
I think one needs to realize that if one comes from and evangelical free church background or primarily un-churched or even independent non-denominational background the objection to boutique religion as some have put it, wont hold a lot of watter. It also may not carry much weight for those in mainline denominations trying to live as Christians beyond the walls of their denominations. This is so in part because from their perspective its not so much mixing what comes from the true church with sectarian traditions but trying to create something from the resources of the broad historic Christian tradition. Tripp mentions the analogy of mixing music by DJ at a club without attribution(Not his but from the seminar). Tripp alls mentions the crumbling walls between denominations which leads to this freely using elements from another's tradition. Though I think for many it is simply trying to appropriate what can truly express and show the faith (or one's faith.) The challenge is for any of us in this context to give expression to a theology of the church, let alone for two competing claims about being the true church to readily make sense. What I would encourage Orthodox and Roman Catholics to recognize is that there is a deeper longing here for many (though I am sure not all) for the church that is beyond Protestant denominationalism. Thus, you will have to do more than just critique the appropriation of rites or practices from your traditions. But also articulate why Orthodoxy and/or Roman Catholicism aren't just denominations.