I think it makes sense to an extent. Sellers are the ones trying to sell and they have the obligation to ensure they satisfy the customer so that eBay continues to be a viable forum for the sale of goods.
THe problem though is how do you as a buyer get rated? THe seller should be able to check that the guy has at least 10 feedback or something. If the guy has zero then tooder-loo.
The most important part still is getting what you paid for. To that extent, I think Paypal and eBay need to look at their limited dispute resolution mechanisms. I mean complaining through eBay can be a massive pain when u've paid for items via bank deposit yet bank deposit is an understandably much more preferable medium to sellers as well as for buyers who don't want to dip into their credit card and be responsible with their expenditures.
So I don't think it goes far enough but it's a start.