There was something going on today. For the first time I saw my phone roaming on band 4. Also saw it fall back to 3g in places it never did before. They are configuring the system in my area. Hopefully they don't screw it up :(.
I definitely have seen new towers.
My logs indicate four new 311 490 towers just on my 10-15 minute drive to work this morning. Considering this is a drive I do at least five days a week twice a day and all had at least one B4 sector, it is highly unlikely I just never encountered them before.