Yep - they are working on setting up new towers and tweaking their 4g service. We stopped having problems in central NC area yesterday, but it's exactly what you all have been describing. 4g with plenty of bars and then it just drops the data side of the connection right in the middle of use. As of yesterday afternoon things seem to have stabilized. The ONLY way I was able to find out that they were working in my area was going to their news website - news.verizonwireless.com and troll through the stories for the last month and a half and find out they were planning on working on the 4g signal in our area. If you are having problems, I suggest you look there to see if you can find news about your area (wish they would find a better way to notify us before they start work) and switch your 4g phones to CDMA (3g) only to retain data connectivity while they are working in your area.
Hope this helps,