Some new details are rolling in for the all white Ultra Boost Collective scheduled for a June 6th release. They will use higher quality materials than the regular Ultra Boost and will also have the white sole unlike the black sole version that was released for pre-order. So far it looks like select boutique stores will be getting these. No word yet if they will be launched on the main site, but keep an eye on the New Arrivals June 6th just in case.
On a related note, Foot Locker mentioned they are supposed to be getting the all white Ultra Boost in stores today and tomorrow. You can use their launch locator to find a store near you which may have them. So far, it looks like not many will be carrying them yet. Stay tuned for any new details about the Ultra Boost Collective as they become available.
Update: You can see detailed pics of the upcoming Ultra Boost Collective over at Solebox.
Update: 6-3-15 It looks like the shoes will retail less than expected as some of the prices at specialty stores such as Sneakers N Stuff are starting to be listed around $220.