You should at least try a demo of Office 2007 before you decide. Personally, I'm sticking with OpenOffice at home and Office 2003 at work. I tried out 2007, but I think the toolbar ("ribbon") is ridiculous. It takes up to much space (though I do seem to remember there was supposed to be some way of hiding it). I don't know, I usually think change is good, if it improves things. But I think the new look is just for the sake of saying "ooh, look; this isn't just another Office rehash."
It was several months ago, though, so I can't remember the details, but I remember I had no interest in upgrading. And everyone's preferences are different. I like to maximize the space of the working area, but maybe other people like having every single feature and button crammed out in the open at the top of the window. You can try OpenOffice for free, and you can try the Office 2007 demo for free, so what do you have to lose?