Windows 7 49.99 Pre-order, or ~120ish OEM for new build?

I'm planning on building a new system sometime in September/October.

I want to take advantage of this $49.99 Windows 7 Upgrade Pre-order deal, but after talking to two different Microsoft Reps, this is what they said:

1. (Good) I can upgrade to Windows 7 x64 bit from Windows XP x32 bit OEM, although it will wipe XP from the drive (who cares? I like fresh installs)

2. (Bad) You CANNOT install windows 7 on a totally blank HDD -- it requires either XP or Vista to be installed on that partition, even if it will wipe it out upon install. I asked specifically if it was like earlier upgrades where you could insert the earlier version boot disk to confirm, and she said no, you need the OS to be installed.

So now i'm torn -- Do I pick up the $49.99 upgrade and then have to go through the annoyance of installing XP first, activating it (pretending this isn't a brand new computer), and THEN installing Windows 7 everytime I have to reformat, or the drive dies, etc. OR... do I wait for the ~$100 - $120 Windows 7 x64 OEM to come out?

On a new Lynnfield or Phenom, how long do you think it would take to install XP? Less than half an hour probably.
How often are you going to reformat or loose a drive? I would assume rarely.

Now let's ask ourselves, is It worth $70 to you to avoid that short process? All you have to do is put in the XP CD and walk away for half an hour.