If you want to experience most of the nifty next-gen features Sony flaunted for PS4, you'll need to download a day-one update, according to the PlayStation Blog. The 300 MB patch (mysteriously numbered 1.50) is annoying though not unexpected, but one convenience will remain unavailable even after installing it: suspending and resuming games.
It's meant to make PS4 titles as easy to pick up and put down as a mobile game: you simply suspend the game when you want to take a break for a while, putting the system in a low-power state, and resume it almost instantly when ready to start again.
Don't let that keep you from installing update 1.50, though, unless you don't want to:
Sony plans to say more about upcoming PS4 features in the near future.