My understanding is the aircraft are being converted to a two class configuration to have a common config system-wide. So, we shouldn't be seeing these show up on other routes (again, from what I've been told). The existing aircraft are basically being de-shuttled and made into the standard mainline config. Ditto with the one class A320s flying around -- they are being converted to standard mainline config. I think the intent here is to allow for better crew utilization, routing opportunities, etc. The Shuttle is no longer the premium product it once was ... Acela is stealing too much traffic.