If I am understanding the question right, the bids development environment would be licensed the same way as your server on a client basis. In other words, if you have a Server license and a number of client access licenses, then if you want to use the bids environment on another machine for development then you must have a client access license for it. If you are processor based then you are ok.
Check out the document link from microsoft...it is for sql 2005 as I could not find one for 2008 but it makes sense to me the licensing would be similar and the "shared" tools are basically based on the client model you are following for your server.
Oh, and yes I have to agree with Lynn on the development...one of the biggest gains of ssis is the config files which makes remote development and deployment to production a breeze...