MSRP is $249 and we go to production the end of the month; I will have some units for reviewers shortly after that.
I think that Communicator would not be the sole reason one would buy an iPad, but it will certainly change the use case for most people from part time, mobile, and conference room note taker to a full time, active roll in your work flow.
In other words, it won't replace your PC, but it will increase the utility and time using the iPad and enhance the user experience a lot.