This is probably opening up a can of worms here, but isn't that what blogs are all about?
So here goes:
I'd wonder about a pastor who felt comfortable conducting a traditional service and then following it up with a contemporary service. I'd question how true to the confessions the traditional service was if the pastor turned around and did a contemporary service later. It seems to be a contradiction to me - and a "why would you even want to" type of thing.
I guess that hits at the heart of Tim's, JK's and now Ben's argument for the concurrence of both. I haven't had to decide about something like that to date, but we don't have a lot of options around here so I don't know that I'd have a lot of options.
Have at it, fellas.