If the Haswell rMPB is about to be released, it likely will have 10.8 installed, as there's not enough time to load the new GM 10.9, package, ship and distribute the new machines in time to accompany a near-time release. In other words, if we are to see them in the next week or so, it will have to be be with a free, later 10.9 update.Epiphany!!!
1) Apple released the first rMBP (15") a couple weeks before ML was released, but it was announced at the same event. Now, Mavericks has a GM seeded to devs. already as of yesterday or two days ago so that could mean one of two things:
a. Apple will ship the new rMBPs on Oct. 15 ('available today') at their event WITH 10.9 preinstalled.
b. OR if they want to wait another week or two for 10.9, then the rMBPs will ship without Mavericks ('available today') at the event date and get a free upgrade when 10.9 comes out.
c. Apple could release the new rMBPs silently on Tuesday (the 8th) = least likely .
The only way I see 10.9 coming installed is if the release is announced 10/22, with availability sometime thereafter -- even with Apple's remarkable logistics system it will take some time to provide the supply chain with OE 10.9 machines.