While I can understand your fustration Dell has and does routinely drop systems. The normal life cycle of a system is 12 to 18 months. Mostly towards the lower. It will remain to see if they provide any drivers for win 7 on that system, or many of the current models still in production.
You will still need to purchase a copy of Win 7 anyways.
How can it drop their system and still show it for sale on their website? I don't see any indication that it is being discontinued.
From the sound of it, the Studio 17 may be replaced before Windows 7 arrives - and it may be MS is requiring that only current-shipping systems as of late October have the option for the upgrade.