Reasons for the trend towards larger sizes is that prices have come down and bezel sizes have come down, so that today's 55" sets are the same horizontal size as yesterday's 50" sets. And people are finding they want the largest size possible and with lower prices, can afford it. If one mounts it on the wall, almost any size will fit almost any room. As 4K comes in, average set sizes are going to get larger, because you can't see the difference in smaller sizes.
Also, Sony and Panasonic are both "de-emphasizing" TV because they lose money on every set they sell (and Mitsubishi just got out of the business entirely). As a result, we're seeing fewer sizes. I am surprised that those models are available in Europe in smaller sizes, but it might be necessary there because you can't discount electronics in some countries and because of VAT, which makes the products far more expensive than the U.S.
I think we're going to see even fewer choices in 2014.
For 2013, in the U.S., Sony's got 12 lines, 19 models in 10 sizes. Panasonic's got 19 lines (7 plasma and 12 LCD), 38 models (17 plasma, 21 LCDs) in 9 sizes. There are rumors that Panny's going to drop the plasma line, even though that's what they're best known for and where their quality is.
The Sony KDL-nnW802a is available as a 47". Last time I checked, the price was down to $1100 (from $1800 originally). In Panasonic's LCD line, they've got the WT60, E50 and E5 in a 47". In the Plasma line, they've got the S60 available as a 42".
I don't keep track of Samsung models, but they've got a zillion, so check their website for the size you want.