If you are sensitive to new releases to production then take a slower approach. 1.90.1 to 1.90.6 happened in just over a day with very big changes coming into 1.90.1 to make the future development in certain directions possible. I think there were more problems found in trunk testing before release than after. I helped test trunk but once everything was fixed for my use of the application server I could no longer add any value since it all worked for me for at least a week before the public release came out. If production was on 1.89.5 and a one week wait were used post next release which I would consider aggressive upgrading to production then 1.91.1 would be where you are today which is mostly license comments compared to 1.90.6.
I am still developing the application I am working on so I follow the releases quickly there to get some testing in but I have some beta production systems up and haven't touched them in several weeks. I guess they call that staging. I also hang onto a copy of the old release until I am sure the next is good so it can be swapped back quickly.
