When downloading an update from Premiere from the adobe website, does the latest update encompass the previous updates?
For example the latest update for PPro CS4 is 4.2.1. By downloading and installing that, does that also install the updates 4.0.1, 4.1, and 4.2 or do I need to download and install each one to get the improvements from each update?
You need just the latest one; the updates are cumulative. So for instance, if you end up having to reinstall from scratch because the update breaks your install, you can go from 4.0 to 4.2.1 in one fell swoop; no need for 4.0.1, 4.1, and 4.2.