I hope they aren't doing Glasto! It sells out LOOOOOONG before anyone even know what bands are playing and don't do single day tickets, so chances of most of us NIN UK fans actually seeing them would be slim!
But i do think they'll do this smaller tour cycle. Festivals can pay for tours so make sense to do them around Europe with the odd smaller show here and there and then a small club tour of sorts back in the US so they don't burn out.