Well, you've already missed out on MacWorld 2006, so you will have to shoot for MacWorld 2007. It's fun, but it can also be pretty expensive, depending upon the hotel you choose and actual conference package you choose. If someone else is picking up the tab, so much the better, but if it is out of your own pocket, just know that it's going to be $$$.
Worth it? Just coming off my first (self-paid) MacWorld, I'd say a resounding YES, but that's me and my particular experience. I loved it and had a lot of fun. Will I do it again? You bet! Already putting money aside for MW2007.....
Edited to add that I'm a recent switcher, only have had my iMac since mid-October and my PB since the end of that month....I heard about MacWorld and for a number of reasons decided that it would be a fun thing to do, so made the reservations and flew out there from the East Coast and had a really wonderful time.
OTB