Perhaps someone needs to test it again with 10.8.3
I just did, still only the CPU shows:
1. Device: Intel(R) Core(TM) i5-3210M CPU @ 2.50GHz
1.1 Hardware version: OpenCL 1.2
1.2 Software version: 1.1
1.3 OpenCL C version: OpenCL C 1.2
1.4 Parallel compute units: 4
I would really appreciate support for the Intel HD 4000 included in my MBP (mid-2012).