SD --
In the future, please post your Project Server 2007 questions in the
microsoft.public.project.server, as this newsgroup is closing down. To
answer your question:
1. Proposals are used by organizations that have a formal approval process
to initiate new enterprise projects. The PM creates a new Proposal,
consisting of high-level tasks only, and saves it. Someone from the
Proposal Reviewers group must then formally approve it, at which time the PM
can convert the Proposal to an enterprise project.
2. Activity plans are using for planning on-going work for tasks that do
not have a Finish date. For example, you could use an Activity plan for a
DBA team to track their work on DBA support tasks.
Hope this helps.