MacSomething:
For all computer hardware. MacBook, Mac Pro.
iSomething:
Phones & Tablets only (i.e. iPhone, iPad) They probably will never rename these two since the branding is simply too strong.
SOMETHING:
Everything else that is new/overhauled under Tim Cook's era.
I noticed this when Apple Watch was introduced. Apart from Apple Watch's branding, Apple's website was revamped at the same time. Even in Apple Watch's introduction video, San Francisco was used instead of the usual Helvetica Neue.
I think it is only a matter of time (many many years) most of the 'i' prefixes get removed.
Apple Watch is the first indication of a company-wide direction change. Notice how the branding is
WATCH.
Bold, all-caps and emphasis on the Apple logo—a complete reversal of the ultralight Helvetica Neue used for iPhone, iPad, MacBook, etc,
Then we got
MUSIC.
Even on iPhone's packaging. Instead of 'iPhone 5', for iPhone 6 it is now ' iPhone'.
I predict after a few years:
- tv to become TV once there is a big update from the current model, e.g. an entire TV.
- Separate apps in OS X for Music and Videos. See how iBooks have already been branched out.
Just like how we miss the iPhotos name, I think we will miss iTunes even more.
I guess they could not stop other companies from using i in their product names, but they can definitely stop them from using the Apple brand.