I had hoped that I wouldn't have to worry about breaking spokes on that monster rear wheel but snapped one this morning. I had no choice but to continue to work; it rode fine but I took it pretty easy. When I got to work I found that another one was loose from the rim. I'm not sure if that came off first or the other one broke first.
I'll take it into the shop today. I sure hope they have replacements for those spokes. I'm not really happy about this.
Edit as of 12/22/2010
I'm editing this because I want to make sure that anyone reading this thread later doesn't get too upset about the broken spokes and decide not to buy this line of bikes. After breaking spokes almost monthly, my bike shop fired the wheel builder and my wheel was rebuilt by someone else. It has now been several months and even without Trek's new spokes, I have not broken any. I have been biking in pretty nasty conditions; it's been very cold, 23-30F mostly during the past few weeks and windy almost every day. I've been taking a route with a fair amount of crappy paving and the bike has been handling it all like a champ. I'm probably cursing it by posting that all is fine, but it sure looks like all is fine. I love this bike and I would not have been riding through this windy period on my non-electric Trek.