If you really feel like you need IS, snag the 100 Macro. From what I have heard its a great lens, it is one I consider snagging on occasion. Overall though, the 135 from everything I have heard is just amazing and it will be in my bag by summer. As for waiting for an IS version, don't bother. Recent prime changes tell ya that is such a lens ever comes out, it won't have that special feel this one has, ---it would probably be 2.8, and cost double what the current one does