UPDATE: I did not go through with the install last night because I was on my work laptop and the only option in the upgrade was to keep NOTHING. My IT department would likely be angry if I wiped everything off of there and I am not 100% positive I would be able to get back up and running with my work VPN setup. At any rate, I plan to install Windows 8400 on my netbook which currently has 8250 build also.
I was excited about all of the rumors of Windows 8 Release Preview being rumored to come out early. When I checked for updates on my Windows 8 8250 machine I saw that I had 23 updates. Excited, I thought that maybe the 8400 update would come like service packs usually do just in big updates.
Windows 8 Release Preview Requires an Upgrade