to be fair and if i remember correct, mozilla wasn't the first browser to have the tabbed feature.
i can't remember who started it but i don't believe it was mozilla...maybe it was opera?

nothing wrong with copying things like that as long as there are no IP laws against it for the sake of aiding the end user....but it would be nicer if they concentrated on fixing the functional side of things first such as all those CSS bugs...they've barely fixed any bugs. MOST of the CSS bugs remain which is what i just don't f****ng get! why not fix the bugs first???
all those bugs make the job of a web designer harder than it should be and in turn web designers don't bother trying to make things the proper way because it takes so much effort and that contributes to the mess that people call the world wide web :/