Apple will discount the version one models to sell them out. They might perhaps keep the 16 gb wifi for schools and such, not unlike having the 8gb 3gs still on the market. but that's likely all.
Or since they already had the big 'new product' launch last year they could do it as online sales start in the afternoon, units are shipping to the store, go to X site to reserve yours and you will get an email when it has arrived. thus avoiding lines if they push it that you must reserve to get one for the upcoming days. And they could pace out the notices to say 100 a day or whatever each store can handle. Or they could do like Verizon and have the online orders start tomorrow afternoon but hold off on the in store for a few days. That way the upgraders will hopefully go ahead and just have it shipped.