Killers would be ok....I was a big fan, but saw them in Montreal and it was the most lackluster performance I've seen in quite some time. Brandon Flowers was a wee bit too arrogant for a band whose album hasn't even been released for a full year.
I think that all of these great bands (I'm sure Bloc Party is next) announced for Europe are to appease the masses since it sucks for them having to go to stadium shows. It's fair that they get a better overall show than NA. People can get excited like it's a double-bill of sorts. I wouldn't be surprised if U2 isn't excited to see some of those acts live themselves. Interpol on only one date? I'm sure U2 will be checkin them out that night.
I doubt we'll be so lucky in NA, but hey, ya never know. Oh, and as for Louis XIV...I have seen a few positive reviews, but unfortunately, you will have to be aware that they've been given the death sentence for all things cool -- check out their Pitchfork review -- it's um...rather harsh (but comical). I'm not saying I take it for gospel, but trust me when I tell you that there is no review that is more powerful right now as to whether the overall feeling of a band is cool or not.