One has to wonder slightly why mobile manufacturers (Apple comes to mind but others are as guilty) try to shrink the SIM.
Don't try tosell the idea that mobiles are getting so small that every cubic mm is needed. Phones have been growing for some time. Actually mobiles reached their smallest size as feature phones, compared to an average T9 entry phone even the first iPhone has been huge, so where is the argument for microscopic SIMs?
OTOH, there are good reasons to keep them at a size that can be manipulated by an adult without special tools. Subscriber Identity Modules are meant to be changed when appropiate, e.g. when wants to use a different phone, a cheap one for outdoor sports, or a different network (when roaming). so shrinking the SIM makes it worse at it's primary purpose.