Palisades are cheap and weak. This patch allows building them also in neutral territory, instead of only in your own, offering a posibility to use them offensively (e.g. around metal mines).
See also D2506, D2534, and D2803.
[EDIT] It also tweaks the capture points a bit. Palisades are neither garrisonable nor directly capturable by soldiers, therefore the current values are not very meaningful. The changed values mean palisades lose one point per second when outside your territory, and recover one point per second when again in your territory, thus the current amount of capture time equals the time (seconds) left it will take to lose control of the palisade.
Previously it took 1200 / (5.0 - 0.5) = 267 s, i.e. about four and a half minutes, which is rounded up to 300 / (2.0 - 1.0) = 300 s, i.e. five minutes.