If you want a pure XBMC solution, I wouldnt wait for it, as I think the devs have much more they want to work on first. Altho, if you have a MythTV box on your network, you can use a python script to interface with the MythTV box in a limited way now (show recorded shows, status of the box, TV Guide) but the person(s) who are working on the scripts are now focusing on being able to schedule recordings now, so thats a big advantage to using MythTV. You can also bypass XBMC and install a MythTV frontend on the Xbox thru Xebian, and use the Xbox to interface with the backend MythTV box that does the recording and you have all the same abilities on your Xbox as you would thru the actual MythTV backend box. If you dont know what any of this means, go to mythtv.org and read up on it. There are links to the Xbox distro for MythTV as well.
The scripts you refer to shorty are for people using DVB cards, and from what I can tell you have to be using mytheater to use that, as I havent messed with it. I myself am using a MythTV box and XBMC's python scripts to watch my recordings, and the MythWeb interface on another PC to schedule recordings. <