Possible wet FIP?

My 11 month old kitty is currently hospitalized with our vet.  We noticed that he was losing weight and wasn't eating, so took him in yesterday.  Tests were ran for FIV/FeLV just in case (both neg), xrays and bloodwork done as well.  The xrays showed a ton of fluid in his abdominal cavity, and enlarged spleen, liver and one kidney.  Bloodwork was mostly normal, with elevated levels related to pancreas and liver.  He also has a fever.  The doctor isn't quite sure what is going on yet - he is keeping him for the day and is pushing fluids, more antibiotics and possibly some steroids.  He mentioned FIP, but said it could also just be something else that caused the inflammation and fluids, and didn't want to give up on him yet.  Which of course, we agree with.  He's just a baby! 

What sort of questions should I be asking?  I am fully able to admit that I am out of my depth here.  I do trust our vet, he has gotten my kitties through plenty of other things before.  And he is a one man practice, with a couple of vet techs on hand.  So I know Todd will be getting lots of 1 on 1 care today.

The vet can take a fluid sample out of the abdomen for testing. FIP fluid is unique to other conditions that cause fluid retention.

Unfortunately, if it is wet FIP, things will progress very quickly.

Here is a good explanation of FIP.  I hope your cat doesn't have it.  No vet wants to diagnose FIP and diagnosis isn't simple, but the disease will prove itself soon enough.  By the time they show symptoms of swollen abdomens and change in the organs, they are usually in pain.  You can control the pain with buprenex, which makes it easier for them to slip away, or you can choose to sent them to the rainbow bridge when you feel the time is right.  Each cat is different, but the disease progresses in all cases.  There has been a treatment that brings about a cure, but it is new and still only in laboratory studies.  The heartbreak of FIP is that it usually takes young cats, from abut 4 months to three years.  With one exception, all the ones I've had experience with have been under two years of age. Wishing you the best and hoping it isn't FIP, but sharing this link so you will understand what it is you are facing if it is.

http://www.vet.cornell.edu/fhc/Health_Information/brochure_ftp.cfm

How is your baby? is he still in the hospital?