Like the previous model, new CBR125R is a lower capacity and tuned down version of the CBR150R available in Thailand and some other Asian countries. It is made to comply with the "L" bike regulations in some countries, such as the UK. Some people got a replacement cylinder and piston, and other parts to tune it up to quite a respectable bike.
The new CBR125/150R, outwardly looks the same as the CBR250R. It shares many parts, including, I guess, the faring. However it has a different frame, and some other components, so it is some 25kg lighter at 138kg.... still a bit lardy for a 150 in my opinion. It makes about 19 hp.
The old model was lighter at 115 kg (dry, add 10 kg for fuel), and I guess would have made about the same hp.
The 125 version for the UK market, and no doubt others, had, and will still have, the hp restricted to comply as an "L" plate machine. In some markets I guess it would be sold in unrestricted form.
Here is the are the India spec 2012 CBR 150 & 250 compared.
Comparing Honda CBR150R vs Honda CBR250R | Tech Specs | Top Speed | Mileage