Any updates Bre?
I'm watching this thread because I have a real similar problem on my 2002 3.8 GT with 93,000 miles. Had it to the GM dealer and been to 2 different indepenent mechanics (3 times for the independents) and each time I get the car there, it runs and starts fine so they can't find the problem.

Sometimes won't start but engine will turn over.
Sometimes won't start and engine doesn't turn over. Starter motor just clicks.
Sometimes it dies while driving down normal (normal smoothness) streets.
Sometimes it dies while waiting at stop light, or a few days ago while in fast food drive thru lane (not a good place but safer than on the street).

When either the car won't start or when it dies, the pattern has been give it a few minutes then try again, and it either starts that time or give it a few more minutes and it starts. One time it died just a few blocks from mechanic and I think perfect, they will catch it in the act and find problem, but, by time mechanics drove 2 blocks and used their "push" truck to push the car back to shop, the car starts fine at the shop.

The independent mechanic that has looked at the car twice thinks the most probably culprit is the Ignition Control Module but would really like to catch the car when it is dead to see because he said it is $350 to replace that.

I'm looking for help too. I've left a message on "Car Talk" radio but haven't got a call back but it's only been 3 days.

If anyone has an opinion, I'm all ears. (newer battery and tried another battery but same problem, checked battery connections and starter connections, clean air filter, new fuel filter, new thermostat, fresh oil, good tranny fluid, removed ignition lock plunger but problem was there before - just listing things to let you know the maint has been done, not that any of these things might cause this problem anyhow).

On edit - the problem does seem to appear more often as time goes on. Been fighting it for the last year but the last few weeks it has happened multiple times. All in all, probably has happened 10 times the last 12 months.