Head leak on 117 (5.6L) engine.

I crawled under the beast last week to evaluate what work needed to be done. Noticed that the oil leak that is from what appears to be the passenger side rear portion of the head on the passenger side. I replaced the spark plugs a few weeks ago, and did not notice any oil in that area from above, so I don’t think it is the valve cover gaskets. From below the oil really (and unfortunately) seems to be coming from the head gasket. At this point I think that it is merely an annoyance, but something that I would like to fix if it can wait. Is this leak a precursor to a nasty oil and coolant mixer disaster, or is it more of an annoyance? I will replace the gasket the next time I replace the timing chain rails and the chain if it is the kind of thing that can wait 3 – 4 years. I’d rather put a diaper on her till then. Is heli-coil necessary when pulling the head (at about 160K miles)? I recall seeing a jig that is necessary because the holes are not all 90 degrees to the plane of the block.

I guess my question is can this be put off (with careful monitoring), or is it a catastrophic failure just waiting to happen? Some engines are very predictable, and I hope mine is one of them. Thanks!