I just read an interesting article from Wired. It seems the micro SIM has no advantages over a normal SIM, other then size.
Now why would something as big as the iPad need a Micro sim, when the smaller iPhone does not? Micro SIM's up until now have only been used for especially smaller phones that do require the space savings. Wired speculates that the reason behind this may be to force users to get another SIM and therefore two accounts with their wireless provider. If the iPad had used a normal SIM, users would be able to easily swap their SIMs between devices.
The article goes on to say, that a normal SIM can be trimmed to the dimensions of a micro, and would fit into the iPad. So I would expect a template for trimming as well as a micro adapter for the iPhone to be available soon. Will keep you posted.
Read the full article at
Wired
Tmart