Pip conversion is an interesting stat but I don't think its getting enough support; I find it hard to get to even 40% pip conversion even when I make large sacrifices on other stats. I think it should be a much easier to get to higher percentages of pip conversion considering that it has a small passive impact compared to something like critical.
More support can be added for pip conversion in a number of different ways. Kingsisle could start making wands, amulets, and decks with way more pip conversion then they have now; as well as adding the stat to other items such as athames, rings, and as a pet talent at some point. This is just my opinion, and I only hope that pip conversion isn't forgotten about as the game goes on.