Why should i update my ipod?

Ok so after a long period of time, i decided to plug my ipod into my computer and there is an update. I have a 20g ipod with the cool wheel with buttons built into it. I got it about a year ago. anyways there is this new 3.1 version, and my ipod works fine but has old software. I searched and searched to find out about 3.1, but there was no list about what they actually updated. I am skeptical about apple and their updates , after hearing about all theese problems. Is there any point to the update, and what does it do?