In my work experience, may mga mommies talaga na nagre-request kung pwede mag stay muna si baby sa nursery. Different reasons: pagod, madaming relatives sa room, gusto muna mag freshen up, may ubo si husband

etc..
Sa recovery room, dun usually lumalabas yung mga requests na ganyan kasi sa RR pa lang, they get to sample holding baby na. Kung hindi kaya, then they make their requests. Sa RR kasi, we help mommy with latching. As in close monitoring kay baby and mommy. Since mommy can't hold baby pa kasi napagod nga, we help with positioning and all that. Pag lipat sa room, ward nurses na yung aalalay but not like in RR na tutok talaga. So the mommies will usually be anxious pano daw kung makatulog sya dahil sa pagod tapos malaglag si baby? Which is real fear and we see that. So sometimes, as simple as "pagod", dinadala si baby sa nursery.
Plus in the nursery department, separated ang well-baby to babies in need of special treatment. May division each hospital department, kahit sa DR, ganun din. May special room for communicable patients.
For mommies receiving blood transfusion, we usually put baby sa nursery talaga kahit well baby. Mommy needs to recuperate first. Safety ni baby ang priority.

Also, babies who have mommies with communicable diseases, nursery din ang punta nila. Minsan, knock on wood, nag toxic si mommy during delivery..., nursery din ang bagsak. Well, different institution, different protocol.
In addition, yes, rooming-in is the latest policy of DOH. We call it UNANG YAKAP. It promotes early latching and bonding between mom and baby. Ang laki ng improvement ng babies namin nung naka skin-to-skin contact versus warmer. Pink kung pink!

Ang cute nila. Yun lang, minsan hindi maiwasan talaga na mapasok sa NICU or nursery si baby.
Here's a video for unang yakap:
http://www.youtube.com/watch?v=k2auB5JgRsM&feature=related