Im not sure anyone will really make the association with Libya (I, for example, didn't know off hand that was where it was for).

I think you're right it is a current fad - and one that will end soon (all these fads are driven from the lack of available "good" domains I guess). But I am not sure it is a fatal choice; of course .ly is going to be lower performing than .com/.org/etc but I doubt by much - it also has the advantage of being quite "natural" to add/type.

Not to mention that it's a pretty lame trend that's bound to be over soon, and then it'll just look out of touch.

Well. invoice.xy where xy is anything that makes the whole domain pronounceable is hard to find. So I thought it was a good catch. I am aware that something.ly is a trend that will be over yes.

Well, "it's just a name" :)

servers are in US and I am in EU if that makes you feel any better.