i don't understand how apple ships ipads. there is apparently no queue, and when you placed your order must not play any role in when it ships.
Order Date: Mar 11, 2011 at 12:44 AM PDT
Not yet shipped
Product / Part No.
Qty
IPAD WI-FI 64GB WHITE-USA
the funny part is that i received my smart cover on saturday... gee thanks apple i have so much use for my cover right now.

It does play a role. It's just not the entire story.
Assuming Apple does things like most major companies, they are told that the factory can create X number of units in time for launch. Apple says, OK. Apple then says, we'll need to make sure that we have 50% of those units available for retail purchase, leaving X-50% available for online. Those units are sold and shipped FIFO (first in, first out).
OK, you probably knew all that. Now let's complicate things with several other major retail partners. That allocation may be closer to 70% for retail now, if not higher.
Complicate it further with multiple skus, 18 of them in all. And those allocations may be different depending on the sku. For example, it may be closer to 90% of the 3G units going to retail and/or the partners, while the 16GB units might be at 80%.
You still following me? Great. Now let's assume that there's a problem at the factory; Apple is told the yields (the number they can make) will miss estimates. If Apple is like a lot of companies, they will honor the retail allocations so as to not damage the relationships with those partners. For example, maybe the 3G ones are having problems. Those allocations may get cut, and the number available online may be very few.
Now, I'm not claiming any inside information or knowledge other than my own speculation. But given that we don't know what the allocations are like, it's not surprising to me to hear that some 3G models aren't shipping as fast, as they may have been heavily allocated to the 3G partners and retail stores.
Likewise, if the factory is having issues with memory or maybe the white faceplates, those may not be shipping as quickly as the lower memory configuration units or the black ones.
A business like this is a tricky thing, logistically. But it makes sense why someone's 16GB Black WiFi-only iPad might ship to someone who ordered at 4AM, while they're having issues getting 64GB White Verizon 3G unit to someone who ordered at 12:45AM.