:: Anyway, for now, you can open them in Aleph One, save them with .save level, and then open them with Weland.
: I am sorry, I am missing a step here, how do I go about doing this?
1. Vidmaster jump to the level you want to open. (Ctrl+Shift+N, or Cmd-Opt-N on Mac)
2. Bring up the console with the backslash key (or whatever it's set to in the prefs).
3. Type, without the quotes, ".save level Whatever_Filename_You_Want" and press Enter.
4. Aleph One will print a success message with the full path to the file. The File Locations wiki page also tells you where to find it.
5. Open that file in Weland and look around.
: It seems, we are almost at the point of being able to do a proper play through of the original Trojan under Aleph One
To be clear, third-party Marathon scenarios will not be supported for the 1.1 release. If it happens to work, great, but we won't be testing that or accepting bug reports involving content not made by Bungie. One step at a time; Lh'owon wasn't burnt in a day.