Very cool project. It would be even cooler if you could actually send your hand-crafted packets to a modifiable host/IP once you're done. To test if the user actually succeeded in creating a valid packet.
The complete Python based graphical scripting environment with import/edit of Pcap files and other goodies beta is scheduled for release in mid-to-end of July. If you want to be a beta tester, follow @wirefloss on twitter.