This whole thing just smacks of desperation on Apple's part.
Digging up an almost 20 year old patent relating to a stylus (if there is in fact such thing) just to sue the competition because they are implementing a stylus when none of the products you currently sell that compete with the "infringing" product use a stylus, nor were they copied in this regard, only shows that Apple is doing this out of spite and bad faith.
This lawsuit can in no way shape or form be taken as Apple protecting it's innovations and IP. Lots of smartphones before the iPhone was unveiled were using a stylus (Sony for example had a couple of models out) and we didn't see Apple sue anyone because of it.
The Newton was discontinued back in 1998, since then Apple has not released a touchscreen device with a stylus and actually rejected and scoffed at the idea when they released the iPhone. Other companies continued to release devices with a stylus after the iPhone was released and Apple didn't feel compelled to sue them.
But now, because the competition has gotten hot and Samsung and other competitors have become a "threat" to their iOS devices, then now they want to sue companies using this patent.
How convenient. That's just an attempt to stifle competition, not to protect your IP