I received the Raspberry Pi 2 a few days back, after a long delay from RS components. I also ordered an RS-designed Raspberry Pi casing meant for the Model B+ (RS part number 819-3658). The Raspberry Pi 2 had the same form factor as the Raspberry Pi Model B+ so I assumed that the Pi 2 would fit perfectly into the B+ casing. My assumption was half correct.
As you can see from the photo, the Pi 2 can be slotted into the RS casing but the Pi 2 does not go all the way down. After some fiddling, I noticed the problem: a supporting arm (circled in green) of the B+ casing was pushing against a chip (circled in red) which was not there in Model B+.
Even though the external form factor of the Pi 2 remained similar to the Model B+, the positioning of the electronic components were slightly altered. The new position of this particular chip happened to be located right at the casing’s supporting arm.
Fortunately this wasn’t a big problem. Filing down the arm to give space to the chip solved the problem. The Pi 2 then fitted perfectly into the casing after the simple modification was made to the casing.