Love or hate STID, I thought Cumberbatch was pretty good until I found out he wasn't some bloke named John Harrison. ;)
Seriously though, he did pretty well with what was a hopeless situation, trying to fill Ricardo Montalban's shoes. I'm looking forward to hearing him as Smaug in part 2 of The Hobbit this fall.
And before anyone starts kvetching about J.J. hiring people he's worked with before, remember George kept hiring that Harrison Ford guy long after American Graffiti.