Adobe Dynamic Link is excellent - but costly!
One of the great new Features of Adobe's CS4 Suites is Dynamic Link. In short, this allows the different programs of the suite to pass their project files to each other without needing to store them in an immediate format. In the case at hand, this allows to import Sequences from Premiere Pro into Encore without the need to render them before. The obvious advantage: Encore can decide on the quality when you output the DVD, which means you will not end up with hundreds of megabytes wasted on the DVD or - even worse - with just a little bit too much, having to render out everything again.
But this flexibility comes at a cost: For each Sequence that you import, Encore will launch a Premiere Pro process (PProHeadless), which will consume quite a bit of memory:
Do not underestimate this cost! My current DVD Project requires about 3 Gigabytes of RAM, bringing the machine well over the 4 Gigabyte border:
My recommendation: If you really want to use Dynamic Link, get a 64-Bit Operating System and as much RAM as your machine can handle. All CS4 Applications may be still 32-Bit (with the Exception of Photoshop) and thus limited to 2 GB per Process, but running 10 or 15 of those 32-Bit Applications will still fill your memory. Yet on the other hand, not using Dynamic Link seems now like loss of flexibility, because the integration between Premiere Pro, Encore, After Effects and Photoshop is excellent in CS4.