Crystalline Sliver and targets
The Oracle text of Crystalline Sliver now says:


  All Slivers have shroud. (They can't be the targets of spells or abilities.)


It applies to all Slivers, not all other slivers. (Which, would be worded that way if that is what they meant.) It means precisely what the reminder text (or the cards old text) says, Sliver creatures cannot be targeted by spells or abilities that have target in the rules text. Fury Sliver still gives Slivers double strike, Muscle Sliver still grants Slivers a +1/+1 Power/Toughness bonus.

What it does prevent is Spells like Assassinate from targeting a tapped Sliver, or Slivers with activated or triggered abilities (or any other Activated or Triggered Abilities) from targeting Slivers with their abilities.