As course content gets more complex and submissions get larger I think there is a need for an advanced restore method to restore large courses in stages would be a valuable addition to moodle2 by working on the principle that its better to have something partly restored onto which you can restore more than have nothing at all.

It should be possible to restore in stages a large course instead of an all or nothing shot when dealing with complex courses or courses with large amounts of content with the restore in control of the order( where applicable) that content is restored.

Advantages
It would allow users restricted by computing resource limitations (possibly outside of their control) to methodically restore a course step by step
It could mean courses could be created from a combination of backup files
It would mean a faster path to resolution for end users by allowing a course admin to restore the important content first.
Courses could be redesigned quickly if users had more say of what and to where in a course the restoring content went to.
If a course backup was too large to extract via php the user would be able to use their own computer and extraction tool of choice to complete that step themselves and then restore in stages

How I would see it working
The user would be asked to provide the basic course backup details so moodle knows what to ask for, this would come from a backup file or the user would indicate the course setup required.
1st steps would be to populate the user details if required.
Then either by section/week/topic or by resource type,size the course restorer would be able to upload the required contents from a backup or indicate where moodle would be able to find them in a repository or re-using existing content,thus reducing duplication.

The Restore Process
Much like the moodle installs/upgrades sequence which provides an output of plugins installation/upgrades steps completed and whether they were successful or not the restore process would understand the limits (php, ram etc) moodle is confined to and would attempt to restore as much as possible on each iteration through the process. Steps that could not be completed could be attempted again by rerunning the wizard or workarounds suggested.(Upload via http failed: upload file using ftp and point moodle restorer to it)

Future Versions:
Advanced restorer might be able to redirect 1 backup to multiple new or existing courses thereby allowing large courses to be split into smaller ones without much manual work.