From the Manalis and Piel labs: http://jcb.rupress.org/content/211/4/733.full
Beautiful work by Son et al and Zlotek-Zlotkiewicz et al. who developed two more precise ways of measuring volume revealed that cells take up fluid to swell in mitosis. This helps them round up, possibly to make space for a nice spindle. Evgeny and I tried to write a decent summary here.