BigLang

So guys, I'm a new member here, but a long-time Chevy owner of my '95 Silverado.
So, the other day, while pulling into a parking lot, the engine just cut out and died on me! Lost power to the radio first, then the idiot lights on the dashboard came on, then the power steering failed, and the engine died on me--all in very rapid succession. But, after putting it in park, I was able to start her right back up without a problem! It's left me hanging for answers and my mechanic won't be able to look at it until the weekend!

At first, I figured it might be the fuel filter, since it's been long overdue, especially with a low tank all the time. So, I brought it home fixed that yesterday, but then driving it again today it died on me as I pulled up to a stop sign. It had made it through town without a problem but then seemed to randomly decide to die just then. Any ideas on what could be causing this problem?

Some additional information about my truck:
95 K2500 4x4 Ext. Cab
5.7 V8 350
170,000 Miles
Starts up without a problem after it dies
Just started to die when my foot's off the gas, but will keep running if I give it a little gas.
Shouldn't be a gas problem with the new filter, but I'm open to suggestions