Very cool find. I can't get the Trogdor toolbar to show though... the others definitely work.

it works for me.
But it should be better if they add this kind of bar and HTML edition for Gmail :-)

A bit of stretch to say that this is proof they are going head to head with Ebay isn't it?

Not that I believe they aren't, just that the presence of some HTML editing capabilities does not prove anything at all.

Lets analyze what I think people use each for:

eBay
-let users sell items (add picture, create a custom HTML item page, etc.)
-let users search for items
-let users buy items (auction style, buy it now)
-let users determine how trustworthy a user is based on a user rating

Google Base
-let users sell items (add picture, soon to be able to add custom html item page)
-let users search for items
-let users buy items (with google purchases)
-let users determine how trustworthy a user is based on a user rating

The only way Google isn't stepping on eBay's toes is because it doesn't do the whole "auction" thing – which is only a piece (grant you a big piece) of what eBay lets sellers do, but the whole idea is basically the same. Link sellers with buyers.

Google Base will never be a replica of eBay, but I do think there is enough evidence to suggest that it will at least put up some stiff competition.