I'm currently in my fifth year of my PhD program. For those who don't know how such things work in the US, I have a small committee of people (my thesis committee) who act as advisors and gatekeepers on my work. They're the ones who gauge my progress, and ultimately give me permission to write my thesis and receive my doctorate. I'm supposed to meet with them every 6 months, and it had been over a year since my last meeting. Because I'd like to actually graduate one day, I was rather nervous about having the meeting. I was more nervous than I realized, and the botched upload reflected that.
Anyway, to make a long story short, the meeting went as well as I could have hoped for and my committee seems to be happy with my progress. I'm looking to get a paper out in the spring, and they'd like to meet with me again in three months time (which will absolutely fly by) to assess where that paper is at, and how things are going. At that point, I wouldn't be surprised if they tell me to write my thesis and graduate.
What I do after my dissertation work has been weighing on my mind for years and years, and it's obviously coming to a head. My boss will let me stay on as a post-doc in the lab for a while, which I may do depending on other job opportunities and progress on my projects. Ultimately though I need to make a decision that's familiar to a few others in my position. Do I stay in science or go try and work on free software for a living? I honestly don't have an answer yet, because I love them both.
I see tons of incredible opportunities in my field right now, and while I'm not the only coder interested in synthetic biology, I'm one who's positioned to get in on the ground floor of the science in a very real way and have a significant hand in shaping its future. On the other hand I spend my free time devouring computing literature, not biology literature, as well as producing software and things related to it. I do this because I enjoy it, and I know I enjoy it on a deeper level than the biology. Would I enjoy it this way if I did it for a living? I've got no idea, since I've never coded professionally.
I'm coming up to the fork quite fast now, and I'll have to choose soon. I know I'm lucky because I do have the chance to choose for myself, but that doesn't make it any easier.