Just reporting in that I upgraded from latest version before 33.1 to it and got no extra extensions/plugins.
Same here. I'd just installed FF a few weeks ago for the first time because I needed it for something (I forget what). I believe the version then was 33.03. I opened it yesterday to what all the hubbub was about and it said it was going to update to 33.1 ... So I let it do its thing.
No sign of eBay anywhere.