People still ask about this topic. If you edit anything that comes from a Canon DSLR, HDV, P2 camera, you can edit natively (using the original footage) but on most computers it will be slow and annoying to work with. If you mix footage from two different formats it might not work at all on older software. Use Media Manager to make all that footage Prores422.
Stay tuned for doing the same thing in FCP X and other tips as we support that application more in the department.