'10 C'Dale Tandem RT2. '07 Trek Tandem T2000, '10 Epic Marathon MTB, '12 Rocky Mountain Element 950 MTB, '95 C'dale R900, "04 Giant DS 2 '07 Kona Jake the Snake, '95 Nishiki Backroads
...not sure how much this will help but our large/small 2010 C'dale Road 2, measured a very small fraction over 27 inches when measured from the top of the seat tubes centers along the stokers downward sloping top tube. But if measured perfectly horizontal from the top of the center of the captains seat tube to the center point of the stoker seat post, the length was right at 28 inches.
Regarding the 2011 models, while I have not seen any in person, every picture that I've seen looks exactly like our 10 model including the 'Made in the USA decals which I thought I read somewhere on this forum was expected to change.
Lastly, one quirk of our '10 model was that regardless of the numbers, the stoker compartment was too long for my 5'3'' wife resulting in her handlebars being too far away from he. Much to my surprise we had a difficult time finding a longer adjustable stoker stem...C'dale did not make one, our LBS had no solution but finally Mel at Tandems East fixed us up with one that did the job.
FWIW our '10 is a nice tandem and while it is not our favorite yet (we still love our '90 C'dale and are a bit more comfortable/faster on our 07 Trek t2000), when you look at the '10s component level, paint/finish quality and overall package for the money it is a real value.
Note: FWIW, Stoker compartment length is typically cited as the distance measured seat post to seat post parallel to the ground (virtual).
When I last checked with someone in the know, the tandems were still being made in the US... about the only Cannondale being made in the US for that matter. It's still a matter of when, not if frame fabrication will be moved overseas. And, yes... the C'dale is still one heck of a nice piece of kit for the price.