This site was last updated in 2002, so I’m not sure how accurate it can be these days.
However, if one presupposes that www.paypal.com accurately takes you to the paypal website, then www.paypal.com/settlement should accurately take you to the settlement page on their site. By typing it in by hand into your browsers address bar, you can be assured of not falling for any funny java tricks and the like.
That settlement page redirects you to another page, which asks for some information. I fall into the statutory claims category, and the information they asked me to fill out was name, address, and date I signed up for paypal. They didn’t ask for any money, nor did they ask for passwords or the like.
The site then made a custom pdf file of a claim form for me to mail in. Since I get there from going straight from paypal’s site, and they didn’t ask f or any account information, i’m treating it as legit.
BTW, according to the settlement site you have to fill out a form to declare what kind of claimant you are:
"If I Do Not Do Anything, What Happens?
If you do not submit a claim and you do not opt out, you will remain in the class, but you will not receive a settlement payment and you will release all of your rights relating to the legal claims in this case. "
Paypal is evidently putting aside $1mil for “statutory damages claimants”..folks who had an account, but never had any problems, but who are due some statutory damages. That’s supposed to be paid directly into your paypal account when all is said and done. Considering that at one time, paypal claimed more than 13 million account holders, if you file, you may get less than a dime in payment, so if you don’t file, you’re probably not losing anything 
Edit to report research:
The settlement website is registered to Girard Gibbs, one of the law teams who had class actions open. Paypal did indeed recently settle, according to CNET News:
http://marketwatch-cnet.com.com/PayPal+settles+customer+suit/2100-1038_3-5233490.html
Additionally, paypalsucks.com (a site devoted to keeping track of paypal abuses) has a story which links to the settlement site:
http://www.paypalsucks.com/forums/showthread.php?fid=3&tid=5223&old_block=0
The kinds of things on the settlement website look very similar to the settlement website of the recent microsoft class action settlment, so I still think it’s legit.