I, too heard them at the show. They sounded great, but a show is a horrible place to listen so I reserve the right to be totally wrong on that. The cable does go into one side. The headphones are actually quite low profile on the head, it's hard to see from pictures without a head in them. The most interesting thing to me was that the drivers are angles toward the ear inside the housing. After talking at length to Katrin (product-line marketing) and Axel (the designer) I found myself quite impressed with the number of factors taken into consideration in the design. I think they are going to be a benchmark product as it looks like they will cover a range starting at $99, and it seems like the performance is going to be quite good.
I'm not concerned with the bail being only on one side, though I haven't investigated the mechanism personally, I have seen the attention to detail Sennheiser practices especially regarding the materials and mechanical properties of their phones and it is typically outstanding.
FWIW, AKG has also just released a couple of new cans at the low end (K71 and K101) that are pretty good. I think we are in for a decade of very competative product developement or Sennheiser is going to race ahead as THE quality headphone maker.