Griffin is here at CES 2012 demonstrating their new Studio Connect peripheral. If you're a musician looking to take recording on the go, the studio connect aims to bring you this with Midi control. The iPad dock adds extra audio inputs and adds Midi connections.
Once you're done you can upload your content to GarageBand or whatever suite you choose. We got a hands on here at CES and while the product lives up to what it says it'll do, it's a bit bulky to carry around form a convenience point of view.