Everything you ever wanted to know about our current understanding of cytoplasmic organization by phase separation, from the physics behind it to the consequences for disease, in one comprehensive review:
Liquid-liquid phase separation in biology.
Hyman AA, Weber CA, Jülicher F.
Annu Rev Cell Dev Biol. 2014 Oct 11;30:39-58.
2016 UPDATE: Also read a new review and perspective by Tony Hyman and Simon Alberti in Bioessays:
Are aberrant phase transitions a driver of cellular aging?
Alberti S, Hyman AA.
Bioessays. 2016 Oct;38(10):959-68. doi: 10.1002/bies.201600042. Epub 2016 Aug 24.
2017 UPDATE: New review in Nature Reviews Molecular Cell Biology!
Biomolecular condensates: organizers of cellular biochemistry. [PDF]
Banani SF, Lee HO, Hyman AA, Rosen MK.
Nat Rev Mol Cell Biol. 2017 Feb 22.