Repair or trade in?

We have a single-owner, well-maintained, never wrecked 2005 Equinox.

In March 2012 we took it in for a 90,000 mile service and new tires, and told the dealership that the a/c was not blowing cold and my washer fluid wasn't spraying. When we got it back, the service tech told me that everything checked out good, no leaks, systems flushed, etc. They did recharge my a/c and replace my washer nozzles.

Wednesday, my battery died. I took the car to the dealership to have it replaced, and told them that my washer fluid stopped spraying again.

The tech called me a couple of hours later and said that my washer lines were cracked and needed replacing, my brake fluid was dirty so the whole system needed to be flushed, and my a/c compressor is cracked and leaking. I got everything else besides the a/c done, that little jewel is $1200.

My real question is, is this the beginning of needing major repairs on my car? It's only worth $5000 and we've already spent $2000 so far this year, and haven't done the a/c yet. I don't mind spending $$ on my car, but I'm more than a little upset that these things weren't noticed at my checkup only 10 weeks ago. I'm not an aggressive driver so I'm very surprised about the brake fluid being dirty (we live in the city!)When it was just flushed in march.