As HotRoderX stated, the Tab is a great little performer, certainly not the fastest or most capable of the tablets that are available, but that is always the way of things these days.
I use mine daily and love it, and as has been stated before, has pretty much taken over as my main tool for anything internet, relaxing etc.
It is fantastic for watching movies, providing that you use something other than the stock player. I use MX Player, simple, effective and supports a wide variety of formats.
For reading books, there are some great readers out there on the Play Store. I personally use FB Reader, although i find the Tablet a tad heavy in the Samsung hardcase, so i will be getting a Kindle for this.
As for Jellybean. The Tablet is more than capable of running Jellybean. I am currently running CyanogenMod10 4.1.1 which is a Custom ROM build of Jellybean [WIP] and runs super smooth, you do however need your tablet to be rooted which is not to everyones liking.
It's only a matter of time before JB is released.