I'm not sure how I'd feel about it. From an ethical point of view I haven't really figured it out. There are persuasive arguments from either side, and actually I think at this very early stage it's hard to make up an opinion. Does this sort of research involve animal testing? If so I couldn't support it, even if the end result was ethical to my mind.
I'm inclined to say "what's the point?" because I don't miss meat, and so it seems kind of pointless to me. But that's not an ethical reason not to eat it, and also lots of people (vegetarians and non vegetarians alike) DO want to eat meat, which is clearly the point, just not one I relate to. The carnivorous pets point is also a good one. Hmm.
I think there might well be other issues involved. These type of things are often hailed as being environmental breakthroughs but I struggle to see how producing meat in a lab is going to be environmentally friendly... I get that it will use less land/etc, but surely it would use more energy? Plus, so far, everything made like this has been reported to be very unappetising, it may well never really taste like meat since it would not have been "used" in the same way meat from an animal has.
So yes, a big ol' "I don't know" from me.