Long time ago i use WatzNew programm. That programm watch for sites, and if they have changes, programm confirm a user about it.
I wrote 2-3 scripts and understand what is main problem... it's site changing. Little changes and scrip not work correctly. I think it'll be long time, until XML come. And i see that problem for AMC is actualy too.
My suggestion to do a user life more comfort: Automatic script updates. If that ll be possibly, author need only to upload script on server (FTP or HTTP Upload), and usual user don't need to check scripts every day... Scrips that be updated will automaticly download to user machine, after programm start.
How can do it. Easy with build in script language.
Funcions that we needed:
1. Download some by http protocol - present.
2. Compare for version changes watching - present.
3. Save updated text (script) to user machine - I haven't seen that function.
So... we need 3rd function, all other are present now...
And also we needed to start that function with progrram start. And host for scripts, but its not a problem

And what is my personal suggestions - scripts buttons, to start any script i want with only one click.