The rust formation is quite normal for the age. I would just put some protection on the engine oil pan, which seems to be corroded at the forward side. Keep an eye on the engine mounts, the one close to the thermostat housing, the rubber is partly cracked. Not that bad yet.
JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.
The only thing I see that's concerning at all is the oil pan like Frango pointed out. I'd look to replace that at some point in the near future.
Tony-13 JKU Sahara, Black. LED white fender lights & signals, JW Speaker LED heads and fogs, LED windshield and rear bumper lights, retrofit Homelink GD opener, LED interior lighting, shorty antenna, weathertech liners, Drake gas filler. Rugged ridge phone mount and hood catches, dead pedal, ventshades, rampage windshield tie down & stops, solid stainless lugs, 20% front tint, sill guards, FMF spare delete kit, OffRoadHeros cargo top, and lots of carbon fiber hydrographics. ToDo list: LED tails, intake, programmer, exhaust, and a bunch of other stuff. 15 Cherokee KL Latitude Edition with cold weather package. Bone stock. PAST JEEPS : 99 TJ Sport, 98 XJ Sport, 04 WJ Limited, 06 WK Laredo, 09 KK Liberty
Like they said nothing thats too concerning. Suspension, motor and tranny mounts, drivelines thats really normal. They are made of a hard and thick enough steel that they will take a very long time and lots of abuse to rust to the point of breaking. Main things to worry about are the thinner steel parts. Such as the oil pan, tranny pan and body parts. If you are really worried about it give a good coat of POR-15 to everything.
The majority of that is surface rust, just clean it all up. You can paint the parts or coat it in something like rhino liner to help protect against the winter salt and that oh so great road de-icing crap that they love to put on the roads.