I am having the same issue on a 13" MBP 2.4Ghz/8GB/256GB, I have been working on it for about 15 hours now, and had 3 freezes. During one of the freezes, I logged in using ssh to see what was happening to it. CPU and memory usage of all processes looked nomal, and I'm quite sure this is not a system wide freeze but nothing more or less than a temporary keyboard/trackpad inability. Making an external connection to the MBP to reboot it, or closing the lid and opening it again a few minutes later will fix it.
My freezes have been with different programs: the first time while typing in MS-Word, the second time while reading a pdf in Preview, and the last time while browsing the web in Safari.
Also reading back through the forums, I don't think it's related to what programs are open or to multitasking. I have been running statistical analyses for about 5 hours out of the 15 (using 1 core at 100% all the time and a lot of memory), while I continued working and had about 30 Word, Excel, Preview, Safari and Terminal sessions open. Nothing happened while doing all of that at the same time. In contrast, one of the freezes happened while I had only one pdf open with Preview and really nothing else at all. So it seems completely unrelated to system use. Or perhaps it cannot run smooth when it's not warmed up enough 🙂.
Also, I'm not entirely sure whether it's limited to certain types of (retina) hardware or not. On the one hand, it seems that a lot of users with problems have a 13"/2.4Ghz/8GB/256GB. On the other, I think that's simply the most reasonable hardware choice and therefore many people might have bought that configuration.
I think it's becoming more and more clear that this is a bug in OSX Mavericks causing these freezes on specific types of hardware. I'm just a little puzzled by the fact that we don's see thousands of posts by now about this issue (Apple must have sold 10 thousands of these systems since Tuesday) and that Apple has not discovered it while testing even though it seems as if all 13" (and perhaps also 15") Retina MBP's are affected.
