Although this is probably of little use now, Biochemical Engineering is not as specialised as the name suggests, or even as I originally thought (I'm a 2nd year Biochemical Engineer).
The difference between the two courses at my University (UCL) is quite pronounced, but this would not be the case at other universities. This is because they are separate departments at UCL. Most Universities will probably share the same first 2 years between the two courses, and as such you won't be "specialising" until at least half way through the degree. At UCL, only some modules are shared between the two throughout the degree, and the two are more separate, with Biochemical Engineering doing considerably more Biochemistry (obviously), and with the Chemical Engineers going into a lot more Physics.