I just turned 30 in August, and I too am feeling this. I have a job, which pays better than many of my friends'. I did not get my bachelor's, as I was offered a full time position by the place I was working, and decided that I'd take a break from school. Besides, I wasn't really sure what I wanted to do. That was 10 years ago.
Now I'm in a job that pays well, but has absolutely horrible hours. In fact, one co-worker left this job after being told by his doctor that it was adversely effecting his health. I don't hate my job, but it doesn't really inspire me.
There have been many "downsizings" and "off-shorings" here, and there are rumors of even further changes.
So, what to do? Do I study my ass off/get certifications (I work in IS), or do I completely change course, and pursue something that I've not yet thought of?
I've been with my gf for almost seven years, and would love to get married sometime soon, but how can I drag her into this uncertainty?