YES!
I suggest getting it. The main thing that bothers me about RPGs is how linear they are and how you have such little say in your own destiny. I've had the game for a month now, I play it every day for 3-5 hours, and I have done ONE thing that corresponds to the main storyline. Everything else I have done has been of my own volition. I've cleaned out a vault by choice, killed drunken people, stolen weaponry from a store and went across the street to sell it to his competitor, made a half-tiger chick fall in love with me, and wiped out an entire inn full of people because I decided they all needed to treat me with more respect. "What's that, lady? You won't serve me?? FINE! How's about I ram this 5'foot broadsword down your throat?!?! You like that?? HUH?!?! Oh! What's that, Random Guy Who Looks At Me Funny?? You want some too??"
Whew. Okay, granted what *I* do with my time on Morrowind might seem a tad, erm...evil. But hey! You don't have to be! You can be nice and help lovers find eachother across the continent, help crack addicts kick the habit, defend your guild's honor, and kill creatures that are disturbing the peace in towns.
It IS a massive game, and as for the time, it took me a couple of hours to get into it, but once I saw the possibilities inherent within the game, it got me hooked. It's as long as you make it, and as for the 400 quests, about, oh....I'd say 360 of those are optional. So don't worry about it taking too long to finish, because for me, the fun of this game isn't bothering to finish. There's just so much shit to DO!
Anyway, get the game, use the map (you WILL need it!), go to morrowind.com's forum for help, and have a blast. Go kill a rich guy for me while you're at it.