A dev commented at length. There is a patch coming Tuesday that they are "hoping" to fix the bolster bug in.
http://www.swtor.com/community/showthread.php?t=621370&page=78Another interesting tidbit: the bolster system flags an item as "pvp" or "pve":
There is a very important note in regards to how the bolster system handles mixing expertise and non-expertise mods on a single item: The short answer is, you shouldn’t do it. The longer answer is, players are much better off than when they decide to make an item a PvP-focused item, they replace all of the mods inside it with expertise mods. The bolster system handles “PvP” items slightly differently than “PvE” items, and putting even a single expertise mod inside an item tells the bolster that the item is a “PvP” item. The result of this situation can be less than ideal for a player in either content channel, and certainly isn’t working as well as we intended. We continue to discuss fixes to this particular issue, but players can work around the problem by making sure they are either pure PvE items or pure PvP items. Note: This is only with mods on a per item basis, mixing different items on a full character is fine.
I don't yet understand how this interacts with their idea that expertise won't use item budget... it sounds as if new bolster is far more complex than we expected and probably over-ambitious.
