EBay knows it has plenty of sellers, but favors buyers now through this new system -- to keep buyers coming back. But some people unfairly review sellers and effectively put them out of e-business with scorched earth feedback.
Under these circumstances, I would not blame a seller for suing a buyer who provided a false review. The seller cannot just shrug it off; his livelihood may be at stake.
So why even have reviews in the first place. I think if there is a problem, the buyer should contact Ebay privately, and then Ebay can work out the issues between the buyer and seller, and keep things between the two parties.