Re: my old title: "Utility Infielder"
I think all good IT folk enjoy solving problems, question whether they are "specialists" or "generalists" is just where these problems are. For me it is software design, its complexity, performance and "fit for purpose". For someone else it might be much broader area. The important pointy is not the area - it's enjoying it.
If you enjoy the work you do, you will keep improving (includes learning new technologies) and you have carrier ahead of you. If you pick something you do not enjoy, any improvement will be very hard to achieve.