Yup, it is... I've done a demo video of using it more than a year ago; see 
http://www.youtube.com/watch?v=sUgkCob63CE
The part that shows OCR'ing starts at 1:17. It's then that I start  
SubRip (decompressed previously). At 1:22, via
 File > Open VOB(s), I press the 
Open Dir  button and (slowly  sorry for the speed, I use Windows emulation,  which needs a bit of time to read the mapped directories from OS X)  navigate to the  VobSub file created in the previous step.
When I  press OK, the OCR window is immediately displayed by SubRip and I start  the OCR process. At first, SubRip asks me to train all the characters  it doesn't recognize: 
T, u, l, e, h, a, n, y, t, comma, 
ä (clicked on the language-specific toolbar below the input field), 
k, I, dot and so on.
Note  that at 2:16, an error message is displayed (probably because I've  selected the wrong subtitle track? Dunno. My other tests with the same  input TS file resulted in correctly readable subtitles.) I (slowly) get  rid of the error dialog and try continuing the OCR process only to find  out the source is, for some reason, indeed messed up. After having  realized this, I save the SRT file (at 2:43) and, finally, at 2:51, I  quickly check out (in Total Commander) the contents of the just-created  (and Subler-compliant) SRT file to show you it's indeed standard.