There are several ways you can do this now.
Depending on which display you have, you can probably purchase a long extending cord or cords for it to connect to whatever ports you have on the MacBook (this may not work with Thunderbolt, I don't know). You would also need to extend the USB connection, and FireWire if you need it. If you have an Apple Display that also powers the MacBook with a MagSafe connection, you'll have to power the MacBook from its own wall power brick instead.
As for Bluetooth, there are plenty of small Bluetooth adapters that plug right in to a USB port, and are very small. You wouldn't notice them behind an Apple Cinema display.
And remember, depending on where the MacBook is in relation to the keyboard, you may still be able to use the built-in BT. If, for example, your MacBook is just on the other side of a wall, you still may be in range, even though you need a long cord to go around the wall.