This may be a stupid question but I have to learn after effects for work and I was wondering if its possible to use all the great stuff (mainly the particle emitters, and the content folder) from motion. Or does after effects come with its own bag of goodies? Thanks.
After Effects has it's own Particle Emitter. You can use all of the "Content" in Motion that are images or Movies. Everything else like the Lines need to be used in Motion because they are built with a tool in Motion. You can always export out those objects like the Arrow but that would be a lot of work. If your on Motion 2 you may find this of interest but once again. A lot of work: http://www.automaticduck.com/products/piae/
After Effects does come with its own content that is worth looking at. Hope this helps and best of luck.
no you can not. But you can always use rendered movies of particle systems inside After Effects. You can also navigate to motion library and use shapes for particle systems in AE. AE have good tools you only need images to make particle systems. I also suggest you get Trapcode Particular 2 for AE as it is the best particle system around.