I'm a Best Buy Mobile employee so maybe I can shed some light on the preorder situation...
Yesterday (5/6) my store received promotional signage for the EVO 4G LTE preorder marked to be displayed today (5/7) which reads "Reserve Yours Today". The signage also indicates that customers purchasing the Evo with a 2 year agreement will receive a $50 BB gift card. My impression was that the gift card will be activated after tendering the phone transaction so it most likely cannot be used on the purchase of the phone itself.
I think the confusion of the Best Buy Mobile employees that many of you spoke to today is based on the fact that we received no preorder processing instructions for the EVO LTE as we typically do for big phone launches. The ONLY thing I've heard of the preorders is from the signage we received, which is unusual since we are typically emailed instructions several days beforehand. It appears that someone in corporate dropped the ball on that one.
If you do preorder from a BBYM typically we charge a $50 deposit but since no instructions were given, I can see why that deposit was waived for several of you. Paying the deposit does not make you any more likely to receive the phone on launch day. Inventory of the EVO for any given store will be based on the number of preorders that particular location receives. So if the distribution center has 500 EVO's to allocate to the stores it services, a higher proportion will go to stores with more preorders. When the stores receives the phones, preorders will automatically be pulled and reserved for the customers based on the order of the preorders. You will receive an email indicating if your phone is ready to pick up on launch day.
As far as the OG Evo trade in program, that promo runs until 6/2 so if the EVO LTE is released before then you should have no problem getting that promo (which only works with a 2 year agreement, not with handset only). So essentially if you trade in your OG Evo (any condition), you'll get the phone for $149.99 plus a $50 gift card which CAN be used on the purchase of the phone.
The phone freedom promo (if you signed up in February) specifically said that it cannot be stacked with other promotions, but since the promo comes in the form of an instant gift card (and not as a discount on the price of the phone) it can most likely be used on the purchase of the LTE based on the discretion of the BBYM manager.
Hope this helps. I'm not working till Wednesday so in the mean time more specific preorder instructions will probably be distributed to employees.