OfTheDamned
The Friendly Undead
Yes, but I'm not sure I see the point. They both ring the same phone. And you can set it to differentiate the two, but then you won't actually know who is calling on your business line until you answer the phone.
If you have a plan that allows for friends and family calling you get 5 unlimited call numbers on a single line and 10 on a family plan. If you set your GV number up as one of those numbers then all the incoming and outgoing calls will be free (as in they don't go against your regular plan minutes). You can also set the GV number (business number) to ring at more than one location which allows you to pick it up on a land line as well. You can also save all your voicemails and text that go through Google Voice on your computer for reference later on (huge help in business these days). The ability to change personal numbers and keep the business number is a big plus as well.
As far as not knowing who is calling, I have never had an issue with caller ID while using Google Voice. There are even settings that force the caller to identify themselves if you want.