it would be very nice to be able to have multiple builds within the same plan. For instance, we have a build which happens on every check in. but we also have a weekly build that runs database scripts, and another which is run to generate junit reports across all builds.

in the above three plans in the same project you need to have three complete checkouts of the project. (and we maintain something like 30 projects!)

This would also be a workaround for another issue we have (BAM-904) in which we would like to have a separate builds of our trunk, and most recent branch. it would help it in this way:

project: trunk,
plan: proj1
plan: proj2

project: branch,
plan: proj1
plan: proj2

In the first case. you could check out the trunk, and for the build, use a subdirecory of proj1, or proj2, etc. likewise for the branch. This will now work now, because we would end up with a build-dir that looked like:
TRUNK-PROJ1, TRUNK-PROJ2, each with complete checkouts. not good. It might be possible to create a symlink, all pointing to one directory, but that seems like it would be fragile.