I'm probably about to set the fox loose in the hen house but...
For the GSR fans ... what did you expect to happen when your "Dream" of getting Gil and Sara together as a couple actually happened?
He is her Supervisor and, as such, any 'relationship' beyond a purely professional one or an off-duty platonic one is - in my law enforcement experience - FORBIDDEN. If they (Gil and Sara) were to 'get serious' about their relationship, one would be required by (most) department policies to move to another shift, or department, or even resign/retire from The Job. Bet you thought, since this is a Hollywood thing, that 'real life' couldn't possibly intrude. That Grissom and Sidle would be able to play patty-cakes off duty and still work on the same shift together. Sorry, that just doesn't happen in 'real life' and if CSI's writers and producers take the show in that direction... they may lose more viewers than they'd want to admit to.
Possible solution: Gil and Sara get serious, he resigns his commission while Sara stays in the lab - she's younger and he's close to 'retirement' age - and Grissom could still be 'on call' as a Special Consultant to the LVMPD Crime Lab, when his special skills with bugs are needed.
Just giving ya'll something to chew on there.
Personally, I seem to recall Petersen talking about leaving the show back before CSI:Miami even debuted. I also seem to recall reading (somewhere) that he misses the stage and the work there, so I'm not all that surprised that he's wanting to return to the stage. Less pressure, even though stage-work can be a right pain in the butt, and I seem to recollect that Billy has been treated in the past for hypertension related illnesses. Give the man a break, he's a great actor, but he is NOT the reason I watch the show. I watch it for the science, the cool special effects and the odd-ball story lines the writers throw at us viewers once in a while.
Out...