Ok, I've noticed the past couple days that my tranny(4L60E) is starting to slip. It's happening at low rpms just after starting to accelerate from a stop. My truck has over 103K on it. Would a simple service(filter and fluid) help with this problem, or should I look into some upgrades of some sort?

Also, what are the 60E's weaknesses? What symptoms do I need look for when having problems with it?