I have the following requirements for building complex projects.

1) Ability to checkout/build multiple projects from multiple repositories (As an example, one project from github, one from bitbucket etc). Currently you can hit "add" button in the repository configuration but I can see that the Jenkins build silently ignores the second repository and only builds the first one.
2) Ability to checkout multiple repositories in different directories with different branchnames. For example I want to checkout branch1 from repo1 into dir1, checkout branch2 from repo2 into dir2. Currently there is only one "advanced" section to specify checkout directory and branch name however it would be useful to have one per repo

It may be possible to achieve something similar using the Multi-SCM plugin however the solution looks very ugly. As all my projects are Git projects it would be preferable to have support for it in the Git plugin itself.