Below is a dealer website with pics of the 2013 36M (Itasca version). Interior color scheme is new. Exterior colors similar to one from 2012, but I think the paint pattern is different. Front and rear end caps are different. Two interesting changes though ... in 2012, the cooktop had 3 drawers below it (if no oven option). Now there are only the upper two. The bottom drawer was replaced by what look like two air vents?
Who knows? Also, between the driver and copilot seats, the small unit with the cupholders and small drawers is gone. Hard to tell from the pic, but looks like it may have been made smaller and moved closer to the driver's side. Could have something to do with making room for the the slide-out generator. The trim around the top of the interior appears to be changed from last year. More like crown molding.
As for the 34B, I don't know anything about the floorplan but did see some thing that said it is now available with stacking washer/dryer instead of the combo unit like the 34Y. Also read that residential type fridge is avail on 34B. I have seen info that confirms what someone said above that the 34B is on the lowered rail chassis like the other Meridians. Also read that the slide out compartment tray on the pass through storage is now standard instead of optional. I think that applied to all Meridians and presumably Journeys. There were a couple of other options from 2012 that are now standard, but I forget what they were.
I noticed on the pics of the 36M that there are two small vertical antennas located at the front of the coach roof. Anyone know what they are for? Were they both there last year? I seem to remember only one but could be wrong.http://www.transwestrv.com/pre_owned_detail.asp?sid=08634455X5K31K2012J12I06I51JPMQ7255R0&veh=2701031&nv=y