So next week I'll be traveling to london (Wed 17-Sat 20) and I'm wondering if there is any chance on getting an Apple Watch Sport Space Grey 42mm, will there be any in store?
You can also try Selfridges in London. They are stocking some models of the Apple watch. You can call them before you go and they will tell you what stock they have. No appointment necessary.
Don't bother calling DSM - they don't say anything other than check in store daily. Just walk in after 11am and you'll either get an appointment or be able to buy immediately (got an SS BCB this way).
Selfridges open at 9.30 and will give out stock info over the phone and tend to get Sport models in.
Regent St are good for bands and may even have some watches by then.